Ah, intention. Philosophers have been musing for ages about intention and whether intention matters. It's a lovely thought, right? And I suppose amongst humans, one could argue that there may be some truth to Seneca's ruminations. When it comes to our porcine friends however, I think that there is no greater folly than assuming that intention has any bearing on behavior. 

Forget about intention. We need to talk about reinforcers. 

(While there are certainly a whole host of various things that might serve as reinforcers for pigs, lets focus on the ultimate reinforcer for just about every pig: FOOD.)

When we intentionally give a pig food, we usually understand that the reinforcer (food) is doing exactly that: reinforcing whatever behavior preceded the food. We ask the pig to "sit" ... the pig gets the treat ... we have reinforced the "sit."

So what about all those times that the pig gets ahold of food unintentionally? We have the very human tendency to justify to ourselves that THOSE treats (reinforcers!) somehow don't count; that they somehow AREN'T reinforcing anything simply because we don't want them to...

Sorry. Intention has no bearing on whether a behavior is being reinforced. If a pig gets into the garbage or steals food from your toddler, those unwanted behaviors ARE being reinforced- whether you like it or not. Your pig isn't trying to be difficult or trying to be bad; he is simply doing what a pig does best and that is finding and eating food. Whether you INTENDED for him to get the food matters not at all. The only thing that matters is whether he succeeded in getting the food. And because food is often SUCH a powerful reinforcer, punishing a pig after he has gotten the food does little except perhaps make the pig more likely to fight or become aggressive or sneaky. There are very few punishments you could implement to a pig that would actually make it not worthwhile for the pig to repeat those behaviors that got him the food in the first place. He might just learn to bite or charge or be sneaky as well. There is really no substitute for PREVENTING the pig from obtaining the reinforcer. Maybe Pig isn't allowed in the kitchen anymore. Maybe the kids are only allowed to eat snacks when the pig is outside. 

Nobody said living with a pig would be easy. But we complicate matters when we fail to understand that reinforcers REINFORCE, regardless of whether we want them to or not. We don't get to choose what reinforcers are to an animal, and to a pig, obtaining food is almost always worth the challenge and risk of punishment. Don't assume that your intentions make a difference in whether a behavior is reinforced, because regardless of intention, if a behavior is increasing, it is somehow being reinforced, even though you (undoubtedly) don't intend for it to be happening! Don't set your pigs up for failure by waiting until they are consistently being rewarded (via stolen food, crumbs, garbage, etc) for performing unwanted behaviors... prevention is key to a happy pig household. ​

​When we talk about pigs and aggression, one of the topics that invariably arise is the idea that as a pig matures, you will start to see an increase in aggression. By about 1-2 years, conventional wisdom tells us that the pig will start to challenge anyone who appears 'weak’, strangers, etc, as the pig tries to move up the ranks of the herd. Is this really what’s happening though? A critical analysis of pig behavior tells us that pig aggression is likely much more complex. Ontogenetic shifts in behavior may play a considerable role in what we currently attribute to maturity-related aggression in pet pigs. 

Before we get to that though, let's first consider what we already know about how pigs behave in a herd and why our understanding of changes in pet pig behavior in the maturing pig may be incorrect:

1) Piglets begin establishing hierarchies as early as 24 hours old! These squabbles between day-old newborns can be FEIRCE. In fact, piglets are born with 8 very sharp ‘needle teeth’, and commercial hog farms routinely clip these teeth to reduce the incidence of facial cuts that piglets inflict upon each other when fighting! They DO NOT wait until they are ‘mature’ to begin fighting with herd-mates and littermates to establish hierarchies.

2) Studies show that normal pig hierarchies are fairly stable – the piglets don’t challenge the older pigs *just* because they reach maturity (Boars are an exception, but pet pigs should be neutered!).  Even if a piglet grows larger than her mother, the hierarchy tends to remain stable, unless one of the senior members of the herd is removed.  If a pet pig truly views you as her ‘leader’, she should not automatically begin challenging you at 2 years of age *just because* she reached 2 years of age.

In fact, there is an interesting disconnect when we use the term ‘maturity’ and aggression in pigs. In general, when considering the concept of an animal that becomes ‘aggressive’ at maturity, we are referring to sexual maturity. Indeed, an intact boar WILL become aggressive as he becomes sexually mature. But potbellied pigs mature VERY early – boars can and do breed at just a few months old and females can breed by 4 – 6 months old. So if we are talking about sexual maturity and the presence of aggression, our time-frame for the development of aggression towards people should be 3-6 months old, not 1-2 years old as conventional wisdom tells us. Of course, pigs that are kept as pets should be spayed/neutered for MANY reasons, and in fact, most pet pigs are – so what might account for the idea that pigs begin showing dominance-related aggression as they reach maturity?

I believe that ontogenetic changes in behavior should be given serious consideration when exploring why so many pigs seem to become aggressive as they get older. Ontogenetic changes – or behavioral changes in response to the same stimuli as an animal gets older – occur in many species of animals. These shifts in behavior optimize survival chances for the animal.

 Indeed, a smaller pig, when feeling threatened or scared, will likely utilize ‘flight’ as the method of choice for responding to the threat (The use of the word ‘choice’ here is just semantics – these behaviors are largely instinctual responses to stimuli). A small pig has little chance of surviving a threat if he sticks around. Hiding or running offers his best chance for survival. Once an animal matures and become larger, the behavior for dealing with the same issue (a fearful or scary situation), often changes to ‘fight’.  Adult pigs have fearsome weapons (tusks) and significant body-mass to use to their advantage. While hiding or running may have offered the best chance for survival when they were smaller and without weapons- they now have additional options for dealing with predators, especially if they feel cornered…

​Often, I hear that a pet pig ‘suddenly became aggressive or  violent’ as it reached a year or two – presumably because it wanted to ‘move up the pecking order’. It’s easy to assume that if no aggression was noted previously. However, very often, there WERE signs of fear from the pig when it was younger,  that either went unnoticed or were ignored by the owner. 

​It’s imperative to notice and respond appropriately to these fearful behaviors. Pigs (and other animals) don’t just ‘grow out' of them. Whether it’s due to inadequate socialization, the use of aversives, or a genetic propensity towards fearful reactions, ignoring or failing to notice and address subtle fear-based behaviors in young animals can have disastrous consequences for both the pig and his family as he grows up.
 
It’s now understood, even with domestic dogs, that behaviors that may have been previously attributed to dominance as a dog matures can more often be attributed to behavioral shifts in response to the same fearful stimulus. Puppies, like many young animals, are quite defenseless; cowering, moving away or freezing is most often how they deal with fearful situations. As a dog matures, he suddenly has size and weaponry (sharp teeth) that allow him to adopt a defensive strategy of fighting to try and deal with frightening stimuli. The underlying emotion, FEAR, hasn’t changed; however the animal’s response to fearful situations HAS changed.
 
So why does it matter? Aggression is aggression, right? Perhaps. But if we as a pig-parenting community are misidentifying root causes of behavioral problems, we may well be further exacerbating those problems. If age-related aggression truly was because these pigs were trying to ‘move up the ranks’, and could be resolved by responding through force or being ‘top pig’, then it shouldn’t continue to be such a prevalent issue for pig-parents. If, however, the aggression we commonly see as pigs age is rather an age-related shift in how the pig reacts to a fearful situation, responding with force or punishment is likely to result in an increase in aggression.

​We must continue to try and better understand porcine behavior and natural history in order to better address, and hopefully avoid, these common pitfalls; both for our own sake as well as for our porcine companions.

When we talk about dominance aggression in pigs, there is often a combination of traits that seem to lend to this description easily. These pigs usually seem confident and will actively approach people, only to charge, snap or bite at the last moment. It's easy to assume this type of pig must be dominant, because a fearful pig certainly wouldn't actively approach a person, would it? Well, probably not. But what about a conflicted pig? 

Let's say I'm a new pig parent. I've done my homework and have read that pigs, because they are herd animals, often try to become dominant towards people or other pets too. I've been told, too, that in order to avoid this problem, I need to be 'top-pig' in our relationship, and so should randomly show dominance or make him move out of my way. 

Because I want to do my best to be a good pig-parent, I start utilizing these techniques - maybe even before I see any signs of bad behavior. That should allow me to build a strong relationship with my pig right from the start, right?  So why do so many pig-parents who utilize these dominance-based techniques have so many instances of aggression develop in their pets? Perhaps they aren't 'good enough' or 'convincing enough' as top pig? Consider though, that often even success with these techniques means a never-ending cycle of needing to 'show' the pig every now and again who is boss. After all - if we assume that it's just in a pig's nature to try to become dominant towards people; indeed, we WILL need to spend a lifetime occasionally battling the pig for dominance. 

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​First - Let me state plainly: Using dominance-based techniques doesn't make someone a bad pig parent, and it certainly may work for some. Pigs are difficult, smart, and challenging and there is no one right way to parent (whether it's pigs, dogs, kids or anything else for that matter!). We are all just trying our best to keep our porcine-friends happy and healthy. And none of us bring a pig into the house unless we genuinely love them and enjoy their company. But therein lies the key to perhaps understanding why unwanted aggression is so often labeled as 'dominance' when in fact, I believe it is often conflict- related aggression instead. After all, it's very easy to see how these behaviors could seem dominant. If pig actually approaches you and then bites, he's obviously not fearful, right? Perhaps, but that doesn't necessarily mean that the pig is displaying dominance-aggression either.

In the typical house-hold where dominance-based behavior modification techniques are utilized, and where aggression develops (either before or after these techniques are employed), I tend to see this type of scenario:

-Pig loves his owners, as pigs do- we all know that pigs form very strong bonds with their people. Pig loves to have people give him belly-rubs and learns to approach them for treats, food and affection. Pig being a pig though... he does still get into mischief. And many of us are accidentally inconsistent with training. Maybe sometimes begging is ignored or punished, and maybe sometimes it earns a (dropped) treat.

-Once Pig starts misbehaving, his owners often double-down on showing dominance or maybe just begin utilizing dominance-based techniques or punishments to try to stop pig from getting into trouble. They randomly move the pig around, perhaps even barking at him, stomping their feet randomly, etc, if he doesn't move immediately when they want him to; or swat him on the nose or yell at him when he is misbehaving. So now for the pig, laying in bed may either earn him a belly rub or it may mean getting randomly kicked out of said bed.

So... how does pig know at any given time whether you're *nice-person who wants to give him a belly rub* versus *unpredictable-person who is chasing him out of his bed*?

Pig still VERY MUCH loves his people. He's just very conflicted. He approaches you because he likes you, wants a belly rub, etc (or maybe because he's been inadvertently taught that begging equals treats)... but because he is conflicted and confused about what type of treatment may be coming his way - he reflexively bites or snaps once he gets to you- just in case you were going to do something he deems unpleasant like show dominance or punish him instead of giving him affection or treats.

We have seen this with many pigs, but one particular long-term resident here comes to mind: The pig in question was surrendered because he was large and INCREDIBLY aggressive. He had bitten multiple people and drawn blood. He is ALSO incredibly outgoing and is the first one to run up to new people. These two behaviors combined seem to shout 'dominant', right? A very large, confident pig who runs up to people and then bites and snaps?

Well, in his case - he's actually not 'dominant' at all towards people. He just LOVES people. He was well socialized as a piglet. But he was also spoiled rotten and started biting when he wasn't getting his way. Once the previous owners started using dominance- based techniques, he became uncontrollable and dangerous. But because at one time, he had positive relationships with people, he still actively sought people out. However, once he reached them, his brain would start screaming something like, "wait! stop! They're going to do something unpleasant!" and then he would lash out, just in case...

Many years later- he is a dream. He doesn't receive any aversive measures here (he also isn't spoiled! Remember, PREVENT problem behaviors first!). He doesn't bite, charge or snap at people, and hasn't for many years, despite us not using dominance-based training methods. If he was truly 'dominant', we wouldn't have just been able to stop using dominance-based training methods.

​But he, like many pigs, wasn't trying to be dominant... he was just conflicted.

Of course, once a pig has started biting or showing other signs of serious aggression, it's not so simple to resolve. In this particular case, it included significant outdoor time & mental stimulation, a very structured routine including NO accidental reinforcement of these unwanted behaviors (not through the use of punishment, but rather through modifying the environment so that the pig didn't have access to things that caused the problems, like being underfoot while people were eating...  and actually in the beginning, he was kept away from all people except for very controlled interactions so that he couldn't practice those unwanted behaviors), and counter-conditioning new, appropriate responses to people along with being VERY consistent in never using aversives or punishment. This pig needed leadership, for sure - but he also needed to learn that he could CONSISTENTLY trust that any interactions with people would be positive or neutral. The appeal of dominance-based methods is that they are *fast*; show dominance and the bad behavior will stop, often very quickly. Unfortunately, from my experience, in actuality, it's a very short-term solution and the aggression almost always comes back even more severely down the road. 

Inconsistant interactions with our porcine friends often lead to inconsistent behaviors from the pigs themselves. Pigs thrive on consistency, both in routine and in their expectations of how people behave toward them. A well-mannered pig is often simply the manifestation of a combination of a consistent routine, the prevention of unwanted behaviors before they happen, and a firm understanding of expectations - both of the behaviors expected of the pig, as well as the behaviors that the pig can expect from his humans.

We all know that a pig is essentially the equivalent of a toddler. And what do toddlers do? Touch EVERYTHING. A pig uses their mouth and nose just like a toddler uses his hands. Of course, we don’t necessarily want Piglet to bite and nose everything in his path, but using punishment isn’t always the best way to discourage these behaviors either. I receive a lot of questions from people with new piglets who are worried because the piglet snaps when they try to touch his face. Is the piglet being dominant? Aggressive? What possible reason could a piglet have for biting and snapping when their owner is just trying to show affection?

Keep in mind that pigs are incredibly curious. They are extremely intelligent animals with an EXTREMELY LIMITING body-shape. They don’t have hands, arms or any other means of investigating like we do. Even dogs and cats have enough mobility in their front legs to reach their face and head. Pigs aren't so lucky... most pigs can, at most (barely), reach their chin with their front hooves. They have poor eyesight and so can’t necessarily rely on vision to investigate things either. What they do have is a snout and mouth. Don’t assume that every snap or bite is aggression-based or because a pig wants to dominate you.  Pigs use their mouths and snouts for MANY different behaviors. Using punishment in many instances only makes a pig more nervous and anxious and can lead to significant behavior problems down the road.

Back to that snapping, swiping, biting piglet...
 
Let’s consider a couple of scenarios:
 
Scenario A: You’re resting calmly in bed, and you’re almost asleep. You feel something brush against your face. What do you do? Maybe you reach up with your hand to see what it is, or brush it away. You realize it was just a stray hair, and so you brush it away, or ignore it, and go to sleep. No big deal. You investigated, found it was nothing to worry about, and went on with things. The next time you feel this sensation, you just ignore it- you know it’s just a hair, nothing to worry about!
 
Scenario B: Let’s say piglet is in bed. He is too cute, and you want to pet him while he’s lying there! Who can resist that adorable little baby?!  You reach over and touch his face, and he whips his mouth around and swipes at you. WHOA! Why did he do that? Well, remember, piglet doesn’t have hands. He uses his mouth to investigate things. He’s a pig- having a person touch his face while he’s sleeping is NOT something that pigs are born expecting. That’s a new thing for him and he’s curious and maybe a little nervous! If we proceed by gently and slowly desensitizing him to this, he will likely learn that having people touching/petting him is really great and relaxing.
 
Okay now let’s explore these slightly different scenarios:
 
It’s scenario A again. You’re calmly resting in bed. You’re almost asleep and you feel something brush against your face. You go to brush it away – well, guess what – it’s a spider, and it bites you as you touch it! YIKES!! It startles you and also hurts! Now you’re nervous and anxious the next time you lay down. How will you react the next time you feel something brushing against your face? Will you assume it’s something benign and ignore it? Probably not… You’ll likely react even more aggressively, jumping up and swatting at it because you are anticipating a negative experience, and are worried you might get hurt again! It's important to note that EVEN IF it isn't a spider next time, you will likely assume that IT COULD BE - one bad experience will change how you react to that sensation for a long while in the future, even if next time it IS only a stray hair brushing your face.
 
Okay, lets go back to Piglet. Piglet is relaxing in bed. He feels something touch his face, and tries to grab it with his mouth to see what it is. You respond by punishing the “bad” behavior by swatting him on the nose, scolding him, or kicking him out of the bed. Well, now Piglet has learned that something touching his face when he’s in bed, means that something bad is going to happen, much like the spider in the previous scenario. Can you really blame Piglet for preemptively biting more aggressively the next time you try and touch his face? Remember how you reacted after you were bitten by the spider?
 
My preference for dealing with this behavior is twofold: first, I simply ignore it. If Piglet is doing it because he’s curious, eventually he’ll get used to it and won’t bother investigating. Secondly, I work on generally desensitizing the pig to having his face touched. I start by giving the pig a belly rub, and then working up to the jaw line. Once Piglet is okay with that, then I begin touching the cheek/snout area. I continue to progress (at the pig’s comfort level) to the nose & mouth. It may take only a few sessions or it may take a few weeks. Don’t rush it. It’s important for a pig to accept having his mouth inspected, and having his ears and eyes checked and cleaned, and if he associates those things with pleasant activities like belly rubs and scratches, he’ll be much more willing to allow it. If he expects punishment when people are touching his face, he will react accordingly by being defensive.

Remember that because pigs have such a limiting body and must use their snouts and mouths to do nearly everything, it's incredibly damaging to immediately label any and all biting or swiping behaviors as 'aggression' and/or 'dominance' related. Consider the many other things a pig might be attempting to do when they utilize these behaviors. Responding with punishment may take a perfectly innocent, investigatory bite and turn it into a truly defensive, aggressive bite the next time. Of course, force-free training does NOT equal permissive parenting, and I never allow biting behavior to continue, regardless of the reason. A careful understanding and thoughtful response, rather than a reactionary punishment, can go a long way in building a trust-based, positive relationship between a pig and his human. 
 
Happy pig parenting!

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A common problem that pig owners face is a pig that becomes defensive – barking, lunging and perhaps snapping. It can occur in a variety of situations, but frequently happens when a pig is lying in his bed, so for now, let’s consider that scenario. Let’s remember too that any behavior that is being repeated is a behavior that is (somehow) being reinforced.
 
“But” you say, “I certainly don’t reinforce this behavior!”
 
Is it happening repeatedly? Yes?
 
“But” owner A says, “I don’t give the pig treats for that behavior!” …
“But” owner B says, “I punish him so he knows he shouldn’t do that!” …
“But” owner C says, “I simply ignore it!” …

Surely ONE of those actions should stop the behavior, shouldn’t it? How is it possibly being reinforced with such different responses from each of these owners?
 
Stay with me… first let’s throw out our human-centric definition of reinforcement. Now let’s head back to Animals 101: Survival Adaptations. Defensive strategies to be exact. 
 
Defensive strategies are just that: behavioral adaptations that keep an animal alive. They can be numerous and varied: there are many different strategies that an animal might use depending upon a variety of factors. One such defensive strategy that is fairly common is actually a two-step plan, of sorts. First, the animal bluffs to try and fend off the attacker: with pigs, this starts as barking, grumbling and charging. The pig might puff up his mohawk, hold his ears out forward, stand with stiff legs, chomp his teeth, etc. He’s trying to look big and bad… “I’m not worth the effort, go find something else to eat!” If that fails to get rid of the threat, at this point, the pig has to make a decision – he will either stand his ground, and try to fight the offender, or he will flee. The end goal is the same for either strategy: SURVIVAL. For now though, we don’t actually care WHAT strategy the pig utilizes. What we do care about is the WHY. Defensive strategies are crucial to an animals’ survival. If a pig feels under threat and resorts to defending itself, the only thing we need to ask ourselves to determine if the behavior was reinforced is this:
 
Did the pig survive?
 
I know, I know… it all seems a little, well, dramatic. Of course we know our pet pig isn’t in any danger when he’s lying in his bed. That doesn’t mean he does, though. When an animal, especially a prey animal, feels threatened and resorts to defensive behaviors, instinctually, that animal is fighting for his very existence. Defensive behaviors are incredibly powerful because they serve the most basic function: to keep an animal alive. 
 
Consider this:
 
Pig is in his bed sleeping. I hear the phone ring and walk by the bed quickly, and Pig startles awake: he barks out of fear. Well, I’m just answering the phone, so I just keep walking, ignoring Pig, and go about my business. I might say to myself, “Well, Pig was scared, but by ignoring that behavior, Pig will see that I’m no threat, so the behavior will stop”.  Maybe not though: In Pig’s mind, his BARKING coincided with my leaving his area, therefore, I have just reinforced that behavior. He employed a defensive strategy when he was startled, and he survived. Pig: 1 – Scary thing: 0
 
(This is similar to a dog that barks defensively at the mailman… it gets reinforced because the mailman comes to the house, the dog barks, and the mailman leaves. The dog goes, "YES! I scared him off!" The dog gets a nice dose of reinforcement every. single. day because the mailman always comes to the door and ALWAYS leaves).
 
How about this instead:
 
Pig is sleeping in his bed. I go to sit down with him to give him some affection. He startles and snaps at me. I go, “what a jerk pig! I was just trying to pet you!” So I punish him by confronting him until he moves away from me and backs down. I win, right? The pig will realize his bad behavior got him punished, wont he? Well, not exactly. In Pig’s mind, he just utilized a different strategy, flight, when he realized he couldn’t win the confrontation. Though the defensive strategy is different, the purpose is the same: to survive.
Pig: 1 – Scary thing: 0
 
In EITHER situation, the reinforcement isn’t something external, like a food reward. The reinforcement is the pig’s continued existence. These defensive behaviors become deep-seated and difficult to extinguish, because anytime he feels threatened and resorts to these behaviors and lives to tell the tale, he is receiving reinforcement of said behaviors.
 
Is it hopeless then? How on earth do we sort behavioral problems like these where reinforcement is something like survival? Well, first, again, let me say that problem behaviors are complex and no two situations are the same. A behaviorist or trainer can be invaluable in helping to determine the triggers and to develop a plan of action. Counter-conditioning and desensitization might be helpful. Teaching alternative behaviors that are incompatible with the unwanted behaviors may also be an important part of solving the problem. A primary goal with any behavior modification plan though, is generally to prevent the behaviors from happening so they aren’t being reinforced. If I have a pig that snaps when I am five feet away from him, then even before I decide HOW to fix the problem, I first make sure I stay SIX feet away. That way Pig doesn’t get a chance to practice those unwanted behaviors so that  they aren’t accidentally being reinforced. Then I can go about developing a plan to actually work through the problems. But an important first step is always prevention.
 
If a behavior is rooted in fear (which is often the case with prey animals like pigs), then figuring out what reinforces that behavior can be elusive.  It behooves us to understand the critical role that defensive strategies play in a species’ evolution, and why these adaptations are so strong. These adaptive responses don’t just disappear simply because we bring a pig into our home and provide food, shelter and a warm bed. The sooner we understand these types of problem behaviors, the sooner we can find a way to resolve them.

​One of the central tenets of dominance theory, with any animal, is that we should model our own behavior off of that of another animal in order to effectively “speak the animals’ language” so that they understand us. Whether we utilize dominance theory or not, it is easy to appreciate the notion that acting like a conspecific might be worth trying (especially if we are at our wit’s end, dealing with a problem pig). However, if the goal is to behave like a herdmate would, we must ensure that our actions truly are “what another pig would do.” Fortunately, there is a significant amount of research into the social structure and behavior of both wild, feral, and domestic pigs, to which we can compare our current ideas and better understand any deficiencies in our current applications of dominance theory. 

Unfailingly, when someone is told that they need to gain dominance over their pig by behaving like another pig, they are told that they must randomly make the pig leave the bed, because this is what another pig would do. It might seem to make sense at first glance… in theory, a dominant pig controls the resources, and so would therefore control whether another pig could sleep in the bed. But what does current research into pig behavior tell us? 

In reality, current research tells us that pigs belonging to a herd actually sleep in communal nests (Stolba and Wood-Gush, 1989). While in fact a dominant pig MAY well push another pig away from a food source, pigs that belong to the same herd DON’T seem to kick each other out of the sleeping area. As prey animals, communal nesting is an important adaptation to help provide social support and protection from predators - it doesn’t make sense, from a survival point of view, to randomly make your herd mates leave the nest. You would both be in a more vulnerable state and more prone to being attacked and eaten by a predator. Studies have shown that even in large herds where the pigs form smaller subgroups to forage during the day (which allows easier maintenance of dominance hierarchies), the pigs all return to the same resting area at night. Additionally, these studies show that resting preference locations don’t seem to correlate to social status within the herd – that is, the dominant pigs do not seem to exert ‘dominance’ over the lower ranking pigs in the sleeping area!

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​So where does this idea come from?
 
Perhaps the impression lies in the behavior of artificial social groups of pigs that are set up in close confinement systems, especially on production hog farms. Unfamiliar, unbonded pigs from different groups that are randomly and abruptly thrown together absolutely will chase each other out of the bed. But why would we want to treat our pet pig like an unfamiliar competitor? Moreover, even when two pigs fight after they are first introduced, they almost always settle down and start sleeping in the same area after they have become familiar with one another. As social animals, pigs are biologically hardwired to seek companionship and the security that nesting with herdmates brings. 

​​Perhaps the notion also lies in the fact that pigs are indeed noisy, do jostle each other and do sometimes head-swipe each other when they are all settling down for the night. But that’s generally just pig-speak for “Hey! I’m trying to sleep! Quit moving around so much!” You might get annoyed and nudge or sharply tell your spouse to stop jostling the bed, but you certainly wouldn’t randomly get up at night and make your spouse get out of the bed over and over again!
 
Conversely, if we are to accept that pig behavior and social dominance within a stable social group doesn’t ordinarily involve chasing herd mates out of the nest, and we have a pig that chases us away from the bed, what might this tell us? Unfortunately, it leaves us with this perhaps disconcerting realization: A pig that is chasing a person from the bed probably doesn’t view that person as a herd-mate, and therefore probably isn’t trying to climb any social ladder … consequently; dominance theory wouldn’t make sense in this application. More likely, a pig that aggressively chases someone away from the bed may view that person as a threat and is trying to scare that threatening thing away (and don't forget - if the behavior is happening repeatedly, it IS being reinforced!).
 
Of course, there are no hard and fast rules about the best ways to manage our pet pigs. There is undoubtedly some logic in behaving like the animal in order to more effectively communicate. But we should be very careful about asserting that something should be done because it’s “what pigs do” when in fact that may very well not be the case.

​One of the central issues with dominance theory is that by definition, it only works if you are right there to control the animal. Dominant animals get priority access to food, mates, etc… so do the submissive animals just always have to wait their turn? Certainly not. In actual dominance hierarchies, the non-dominant animals often develop alternative strategies in order to secure food and mates. Across species, males that are not the dominant member of the group still find ways to mate with females and pass on their genes. They just learn to be sneaky, to wait until the dominant male is otherwise engaged, or is far away. They don’t just automatically give up trying to find mates because they know they aren’t the dominant male. The same goes with procuring food… did you know that low-ranking capuchin monkeys will give false predator calls that cause the rest of the troop to drop their food and flee up to the trees? They then have the opportunity to grab the food and eat it quickly before the more dominant members of the group return! In fact, if you have two pigs, consider what happens if the lower-ranking pig finds a pile of food when the dominant pig isn’t around. Does the submissive pig leave the food alone because he knows the dominant pig controls all the resources? Absolutely not! He will frantically eat as fast as possible until the food is gone or the dominant pig shows up and pushes him away. These lower ranking animals don’t automatically relinquish all resources because they aren’t dominant. They simply get creative.
 
So if we want to use dominance theory as a way to manage our pigs, we should be aware that it will ONLY work if we are right there, ready to stop a behavior. When a pig attacks someone or something (whether it has anything to do with dominance… that’s a topic for another day), I often hear people exclaim that we must attain dominance over the pig so that the pig knows that we control the space and stops attacking. Well, it MIGHT work… so long as we are standing right there. Are you prepared to stand within striking distance of your pig for the next 18 years? Pigs are sneaky and clever as it is. Manage them through force and they will just learn alternative strategies for getting what they want. On top of that, we often risk further exacerbating aggression problems by using force and punishment when we want to stop a behavior.
 
More effectively, why don’t we make sure to control the environment so that Pig doesn’t get into trouble in the first place? If Pig can’t get into the kitchen to open the cupboards, not only will we avoid being tempted to use aversives, but Pig also wont have the opportunity to learn to be sneaky and to go into the kitchen when we aren’t looking or aren’t paying attention.
 
Managing the pig’s environment to prevent problems is one of the most effective ways of avoiding problem behaviors. Showing your pig that you are dominant probably won’t stop behavior problems; it will simply create a pig that learns alternative strategies for getting what he wants. Controlling the environment to avoid behavior problems in the first place often leads to more successful, less stressful relationships. While it might be possible to manage a pig through dominance, we should be aware, scientifically, of what dominance actually is, so that we know what to expect. Attaining dominance over a pig won’t lead to a pig that automatically behaves and stops getting into trouble. It will lead to a pig that is sneaky and devious about getting what he wants. 

​Pigs can be incredibly challenging pets… and once they have learned a few bad behaviors they can seem downright impossible. As we all know, pigs are exceptionally smart and can also seem unbelievably stubborn; successfully changing behaviors can be time-consuming and frustrating. On top of that, often when we try and change a behavior, it seems to get even worse! Today I'll be addressing extinction events and variable ratio of reinforcement - understanding these concepts will go a long way in helping us maintain our resolve, and hopefully sanity, as we work through problem behaviors with our pigs. Let’s consider a common scenario with a housepig:
 
Pig wakes us up every morning at 4am by screaming and we give him his breakfast to get him to be quiet. How do we stop Pig from waking us up every morning? Well, in order to change problem behaviors, we need to first identify HOW the bad behavior is being reinforced (remember: if you have a pig that displays problem behaviors, the behaviors are SOMEHOW being reinforced. It may not be obvious at first, but animals don’t continue to repeat behaviors that don’t receive reinforcement). So let’s say that we have identified the reinforcer – feeding Pig when he screams at 4am. So we either completely stop reinforcing it or greatly reduce how often we reinforce it, and… It doesn’t have any effect  - or more commonly, the bad behavior gets EVEN WORSE than before. What went wrong? First, let’s consider a different scenario that might be a little more familiar:
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We have a laptop computer. We go to turn it on one day and it doesn’t turn on. Do we immediately assume that it’s broken and give up? Of course not- we would certainly try several more times to get it to turn on. Our actions (turning on the computer) have been rewarded consistently in the past (the computer turns on), so we have received reinforcement that it SHOULD work. What happens if our computer is older and has a history of being finicky about turning on? We would likely try EVEN LONGER to get it to turn on before giving up, because we know eventually, our actions will probably be rewarded and the computer will turn on.
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These same learning principles apply regardless of species. So back to Pig –  remember, Pig wakes up at 4am every morning and we now know that by feeding him, we are reinforcing that behavior. So we decide that we will ignore him when he screams. The next night, Pig starts screaming at 4am. We ignore it, but it doesn’t stop. In fact, Pig screams EVEN louder now! Why is this? Pig is demonstrating an extinction event, or extinction burst. When a behavior that was rewarded previously is no longer rewarded, Pig will initially perform that behavior even more intensely or vigorously than before. Remember the above example of our computer not turning on! It is no different for Pig – he assumes that maybe we just can’t hear him, or maybe if he screams JUST A LITTLE LONGER, he will finally get food (and depending upon the behavior, it can take days, weeks, or even longer to see a change).
 
So what if we work really hard to ignore pig for several nights, but in a few days, we are exhausted and we just need him to be quiet so we can get some sleep, and so we give in just once? What if we only give him a treat every now and then, but not every time he screams? We might think to ourselves, 'well, surely the behavior will decrease because I’m only giving in occasionally and so Pig isn’t being rewarded all the time.' This is VARIABLE RATIO OF REINFORCEMENT, and it is actually even more powerful as a reinforcer than continual reinforcement. Remember how our laptop is finicky and sometimes takes a while to turn on? Because of this, we are MORE persistent with our attempts to turn it on. Pig is no different – if he is occasionally rewarded, he will persist EVEN MORE with the behavior that sometimes gets him treats.

In fact, variable ratio of reinforcement is one of the reasons why punishment tends to be so ineffective with pigs. ESPECIALLY if the reinforcer is food, there is almost no punishment that would be severe enough to stop a pig from continuing to try to obtain it, even if they know punishment is likely. If your pig snaps and grabs for food in your hand when you’re sitting on the couch, and 9 times out of 10, you scold him and push him away, but every 10th time he tries it, he manages to get a piece before you deliver the punishment, he WILL be on a schedule of variable rate reinforcement, and he WILL continue to do the behavior. You have simply turned your pig into a gambler. Unfortunately with pigs, they are also smart enough to know that 9 times out of 10, they will receive punishment instead of the reward, which makes them proactively aggressive and anxious, because now that behavior not only occasionally leads to rewards, but other times, that very same behavior leads to punishment. It makes for a very frustrated, confused, aggressive pig. The single most effective method for stopping bad behaviors is to remove the chance for reward 100% of the time. It can’t be 97%, or 98% or even 99.9%- that’s not good enough with pigs. That might mean fundamental changes to your household. Maybe pig isn’t ever allowed in the kitchen & dining area, and that is the ONLY place where people-food is allowed (no one ever said house-pigs were easy!).
 
(Here’s something else to consider:  Do you have a friend who is sometimes super fun to hang out with but other times is a total jerk? Why do you continue to spend time with this person? Because you are on a schedule of variable ratio of reinforcement – when you hang out with your friend, you hope that you will get lucky and this time will be fun…  and even if it isn’t, you know that next time might be!)
 
Why do we spend time at the casino when we know that our chances of being rewarded are extremely low? Why does Pig keep trying to get into the garbage even though he only occasionally succeeds? Because variable ratio of reinforcement is incredibly powerful, whether we’re a person or a pig.
 
When it comes to behavior, we’re all gamblers at heart.

(Author's note: there are likely several factors that influence aggressive tendencies of individually-kept pigs - this is part one)
​
​In the wild, a social animal like the pig depends upon it’s herd mates for detection and defense against predators, as well as other important social-feedback functions. A lone herd animal in the wild has little chance for survival. While we are quick to acknowledge that pigs are herd animals when we use it to justify dominance theory, for some reason, we forget that the most vital element of herd formation is protection from predators; and that essential knowledge should impact our perception of the behaviors of pigs that are kept individually.
 
Studies show that many species of livestock, when kept in isolation from their conspecifics, show an increase in frustration-based and aggressive behaviors. However, there actually isn’t solid evidence to support that this is because they then view their handlers as their herd mates or that the aggression is dominance based (remember that dominance is a RANKING of two animals with regard to multiple resources like mates and food). Rather, when a herd animal is kept from members of its own species, the resulting behavior is known as isolation-induced aggression. Some of these problem behaviors are thought to be caused by the lack of feedback from conspecifics regarding appropriate social behavior. This DOESN’T mean that the behavior is related to dominance! More importantly, in an animal that relies on social contact and support from its conspecifics, the lack thereof, and resulting frustration on the animal’s part, can lead to low-levels of chronic arousal and stress and the resulting frustration may then be vented in the form of aggression towards humans and other animals in the household.
 
It is also important to note that there are few studies, but the current research that we have regarding social isolation in livestock where a human handler acts as a surrogate or herd mate shows that while it might lessen the behavioral responses of isolation induced stress, it DOESN’T reduce the endocrine response to isolation-induced stress. Sorry… while we might like to assume otherwise, our pigs probably know that we aren’t another pig.
 
So what can we learn from this information? Certainly, we shouldn’t feel guilty if we have a single pig as a pet. Fortunately, pigs tend to be highly adaptable to a variety of situations and many thrive by themselves in the right family and household. However, many pigs, due to both genetic and environmental factors, tend toward being reactive and nervous when kept individually (which can be exacerbated if they have received punishment in the past or are inadequately socialized). For some households, luck-of-the-draw and/or the particular household situation might land us with a single pig that isn’t capable of coping without herd mates. If we misinterpret their defensive-aggression, frustration-based and reactionary behavior as dominance, we may simply make those unwanted behaviors more pronounced as that nervous, fearful pig becomes even more so.
 
For these pigs, the addition of a herd mate can greatly improve their quality of life, lower their stress levels and might, with little effort, reduce defensive and aggressive behaviors. In other words, this pig can let his guard down and relax, because he no longer has to keep a constant look-out. If we have a single pig that is exhibiting aggressive behaviors, getting him a friend might just be a great thing to do for him. Two pigs really are better than one… just maybe not for the reasons we’ve heard.

In a fascinating study of young pigs, researchers found that pigs that were pushed away when they tried to make physical contact with a handler did NOT show a decrease in their attempts to continue to make contact. However, these pigs DID show an increase in frustration-based behaviors. The potential implications of this finding with regard to how we deal with problem behaviors in pet pigs is significant.

In this study, Repeated Handling of Pigs During Rearing. I. Refusal of Contact by the Handler and Reactivity to Familiar and Unfamiliar Humans, researchers looked at pig behavior in the presence of humans under different handling treatments. The groups of pigs were designated as follows: Human Interaction (HI), Refusal of Contact (RC), and a third control group that received no contact. The pigs in the experiment were 11 week old castrated males and the experiment lasted 40 days. For the pigs in the HI (human interaction) group, the handler tried to encourage physical contact through a predetermined protocol, starting with using voice and progressing to mutual physical contact and play ("Behavioral indications of acceptance were the following: nibbling the handler’s hand (in response to catching of the pig’s rooting disk), shaking its head (in response to catching the pig’s ears), active participation in play (pig catches sleeve and shakes the handler’s arm, pig catches zip of overalls, etc."). For the pigs in the RC (refusal of contact) group, the handler discouraged any physical contact - if the pig made physical contact with his nose, he would be pushed away. If he tried to nibble on coveralls or zippers, he would receive a tap on the nose. As we might expect, the researchers found that over time, the HI pigs increased physical contact (up to 35% of their time) with their handler. More interesting though, is that the researchers also found that the RC pigs maintained the same frequency of attempts at physical contact with their handler over the course of the experiment, even though they were pushed away any time they tried to initiate contact:

"Motivation to interact with the handler was high even for RC pigs. Although these pigs were consistently pushed away whenever they established physical contact with the handler, they persisted in trying to establish contact throughout the experimental period, and as often as HI pigs. Their interest in the handler is further underlined by the fact that, when in the pen half away from the handler, they were oriented toward her as often as HI pigs, and that during locomotion, they oriented more often toward her than HI pigs."

While the frequency of attempts at physical contact by the pigs didn't decrease over time, the researchers did find an INCREASE in frustration-based behaviors by these pigs...

"Compared with HI pigs, RC pigs showed more snout contact with the wall, rubbing, locomotion, and immobility. Pigs of the RC group showed a shift in activities over treatment weeks. Levels of immobility were higher from the first recording day onward and showed a nearly fourfold increase over the treatment period, whereas locomotion and rubbing decreased. Increased levels of these activities compared with HI pigs may be partly explained by an altered time budget, as the pigs were denied continuous contact with the handler. Increased oral activity, locomotion, and immobility have further all been observed in various aversive situations, believed to cause frustration (see above; Vestergaard, 1984; Dantzer et al., 1987; Terlouw et al., 1991; Bishop et al., 1999; Lewis, 1999). The shift toward immobility may be caused by the increasing certainty on the part of the pigs that contact with the handler would not be allowed, resulting in increasing frustration."

What does this study mean for us? There are a couple of really interesting takeaways. Firstly, domestic pigs, by their very nature, tend to seek out humans.  However, piglets don't inherently know appropriate behaviors with people and sometimes bite, jump or otherwise engage too roughly (much like an exuberant puppy). Unfortunately, if we interpret these behaviors as dominance or use punishment to try and correct them, it can seriously affect future behavior. Of course, in this study, the pigs in the RC (refusal of contact) group were pushed away ANY time they attempted to make contact - our pet pigs hopefully would not encounter this level of distance from their owners. But often pet pig owners use these methods, at least in part, to manage behaviors of pigs, and this offers some insight into how pigs respond when presented with this type of treatment. It is also important to note that in the HI group, pigs were not discouraged or punished for nibbling hands or rough play, because these are signs of behavioral acceptance. While we may not want to encourage these specific behaviors in pet pigs, we certainly don't want to discourage pigs that are showing acceptance of us! Especially if we are dealing with a young pig that is curious about people but doesn't understand how to interact properly (nips, jumps or engages in other inappropriate behaviors), it becomes essential to help the pig understand what IS expected of him. Using punishment like pushing him away doesn't teach him what he SHOULD do, and can lead to significant frustration for the pig. Two things of note:
 
          1- Pigs who get pushed away from their handlers show more behaviors associated with frustration, such as standing immobile, nosing the floor or wall, etc. While this study was relatively short (40 days), frustration behaviors in pigs can shift over time - so if we push our pig away when they behave inappropriately or to show dominance over the course of months to years, it is certainly possible these frustration-based behaviors would intensify or worsen over time.

          2- The more interesting finding of this study is that pushing the pigs away when they made physical contact with the handler DID NOT decrease the attempts at physical contact by the pig! If you push your pig away because he is behaving inappropriately or to show dominance, the pig may well keep attempting to make physical contact, all the while becoming increasingly frustrated and anxious because he doesn't understand why he is being punished. More significantly, if light shoving doesn't discourage the pig, you may escalate to more forceful methods, which in turn can lead to fearful responses by the pig that have the potential to turn into fear-related aggression in the future.
 
Of course, this doesn’t mean that you need to let your pig make physical contact with you anytime he wants. Boundaries are important for pet pigs, but the single most effective way to manage problems with pet pigs is to prevent the unwanted behaviors from happening in the first place, and short of that, redirecting your pig to a more appropriate behavior or action if you notice him doing something unwanted. You can use a crate, kiddie gates, or put your pig outside if you don’t want him bothering you. If your pig behaves inappropriately when he interacts with you by being too mouthy or pushy, you might use methods like positive reinforcement and negative punishment to help your pig learn the proper way to interact with people (check out the Case Studies page for more information).

​Terlouw, E. , & Porcher, J. (2005). Repeated handling of pigs during rearing. i. refusal of contact by the handler and reactivity to familiar and unfamiliar humans. Journal of Animal Science, 83(7), 1653-1663.