Guinea Pig Fight Club

Introducing new guinea pigs to a herd is always a stressful experience for the pigs, and can be even more so for their owners if they don’t know what to expect. Guinea pigs are incredibly social and do best in groups, and their health and life expectancy can be negatively impacted from living alone. You should never keep a guinea pig alone if you can avoid it. However, even though they like living in groups they must establish a proper dominance structure. The alpha wolf idea is certainly a myth, but the alpha guinea pig? Well, that is another matter entirely.

Now, the former science teacher in me needs to emphasize that there is frustratingly little research on guinea pig social behaviors that I can find out there. So I can’t really say that they do the dominance dance because they’re establishing a pecking order, but that’s the nomenclature that has developed around guinea pigs so I’m going to use it here. I haven’t found any formal research that offers any explanation for this behavior, which is frustrating considering how much guinea pigs are used in scientific research but that’s a rant for a future post. Just know the dominance dance is something you will see happen with your pets, and there are great guides online about how to guide your pigs through this process. I’ll specifically call out the guinea pig forum as they have one of the most comprehensive guides out there and it was incredibly useful to us the first time we did introductions.

What is lacking in online circles even, is just how intense this dominance dance can be without there actually being any problem between your pigs. I’m not going to recreate some of the excellent guides out there on how to do introductions with guinea pigs, but I will walk you through how re-introductions went for us because at times it can be very worrying but you must not intervene unless absolutely necessary. Constantly introducing and separating guinea pigs can be stressful for them as they need to re-do the entire dance all over again.

Reader Introductions

Some introductions are in order for you, the reader, on the current slate of guinea pigs in my home.

At present, we have 4. Vanya and Klaus are our oldest and we’ve had them the longest. Before my partner and I knew each other back in August 2020, a classmate of hers told her about some 6 month old guinea pigs that came into their animal rescue. They were found in a too-small cage next to a dumpster behind a convenience store, Vanya and Klaus were thrown away by their previous owners. She picked up the pigs from the rescue and has had them ever since. I’ve known these two since my partner and I started dating in April of 2023. They’ve lived with me since May of this year when my partner moved in. My partner really loved these piggies but to be completely honest, I was indifferent and didn’t really want any pets until she moved in and I got to know their personalities. Now I can’t imagine having a home without pet rodents. As you might’ve noticed from the general vibe of this website and my online presence in general, I’m kind of obsessed.

Mai and Ty Lee joined us in June of this year. Similarly, a coworker of my partner called her because their relatives had dropped off two intact males at their home. This coworker has a male guinea pig who had just lost his mate so it was a perfect pairing they were told. Their relatives had bought them from a pet store a few months prior for their kids, but the kids weren’t interested in them anymore so they wanted to re-home them somewhere that could take good care of them. After they were dropped off in a dog crate that was their only habitat, the coworker realized these two intact males were in fact two intact females, which is when she called us to re-home them a second time.

When we got Mai and Ty Lee they had never had hay and would not eat it when offered, they also would not eat pellets. They were only being given an unknown foraging blend of pellets and like with most foraging blends they picked out the dried fruit that is terrible for them and left the rest. They were in very poor shape health wise, very picky eaters when it came to fresh veggies, and they hated being handled to the point they were endangering themselves trying to jump out of our hands. After we had a brief quarantine, they learned to eat hay from Vanya and Klaus, and were also taught to be far less picky eaters by Klaus eating anything that would fit in his mouth (often times even if it was already in their mouth). We also acclimated them to handling so they both now at least tolerate being picked up and accept their fate and stop squirming once they have been. They are now quite happy and healthy adult sows.

Vanya

• Age: 4 years, 9 months
• Gender: Sow (intact)
• Breed: Abyssinian
• Hobbies: Tormenting Ty Lee, screaming anytime she hears the fridge open, being an absolute social butterfly with humans, letting Klaus think he’s in charge.

Klaus

• Age: 4 years, 9 months
• Gender: Boar (fixed)
• Breed: American
• Hobbies: Food, pooping everywhere, flipping over hides and food bowls, blocking the entrance to the lower area of their cage, telling everyone he’s in charge.

Mai

• Age: 11 months
• Gender: Sow (intact)
• Breed: English Crested
• Hobbies: Track and field, imitating a door hinge in need of lubricant, hiding from the world just like her namesake, and stealing food out of everyone’s mouth just to drop it somewhere.

Ty Lee

• Age: 11 months
• Gender: Sow (intact)
• Breed: Abyssinian
• Hobbies: Gymnastics, climbing the hay feeder, finding new and innovative ways to hurt herself, draining my wallet with vet visits, tormenting Vanya right back.

Why were they separated?

Back about a month ago, Vanya became rather aggressive towards the other pigs, particularly Ty Lee. After taking Vanya to the vet and getting some X-Rays, we found out she had some pretty bad gas and was in pain. This coupled with the fact that Ty Lee was likely challenging Vanya’s place in the hierarchy means we had a lot of fights seemingly out of nowhere. We were given some medicam for her pain and fixed her diet until she felt better, but unfortunately during that time she managed to get into some more tussles with Ty Lee and managed to hurt Ty Lee’s ear. She did not ever intentionally bite Ty Lee, but her repeated “get away” and dominance nips, coupled with the dry air at the time resulted in her rubbing Ty Lee’s ear raw and her developing some gnarly sores. This also made it look like Ty Lee may have caught ringworm, and we did not want to give that to our older pigs. Fortunately that came back negative.

Originally we separated just Ty Lee out of concern she might spread ringworm to the other pigs, but she was very distressed until we re-united her with Mai. Ty Lee actually hurt her eye and needed medicated eye drops for a week because she tried to squeeze her head through a one inch hole in our divider to get back over to Mai. The plan has always been to re-introduce everyone once we knew they were all healthy because when they are, they do like each other quite a bit. We are now at that point, but since it’s been so long, we want to make sure we do this on neutral territory and give them a clean scent free cage with lots of treats to go back to when we’re done. And since the first time, we were not prepared for the absolute thunderdome that is introducing guinea pigs, we figured we’d document the process so other people can see how intense it gets.

The Thunderdome

Compared to the first introduction between these four guinea pigs, this re-introduction went rather smoothly. Like last time, the worst was at the beginning. Also like last time, the main fights were not between the pigs we expected. In the first introduction the worst fights were actually between Vanya and Klaus which made me very worried their bond had broken, but this kind of behavior with mated pairs can be expected during bonding. Klaus is very protective of Vanya so when he sees another pig doing dominance displays at her, he gets involved and lunges at the perpetrator which often ends up scaring Vanya so she then lunges at Klaus and you can see how this becomes a self-sustaining cycle. The trick is to keep a close eye on these interactions and make sure they never go outside the minor ear nipping and chattering phase and that one or the other backs down. But don’t interfere at the first nip of the ear, they are not biting each other unless you see blood, they’re really dragging their teeth lightly across their skin. Think of these nips as more of a threat than actual attacks. If you interfere when it isn’t needed, you may confuse them, or worse frighten them into actually drawing blood on their next lunge.

Anatomy of a Guinea Pig Brawl

About 10 minutes in to our bonding session, I got the footage I was hoping to see for this post. Ty Lee tried to steal a bell pepper from Vanya, but Vanya pulled it away. Ty Lee didn’t like this and lunged at Vanya.

Like I mentioned above Klaus does not like Ty Lee messing with Vanya so he started rumble strutting at her to say “not cool. back off.” You can see as this happens Ty Lee assumes a frozen position with her body tensed and her head held high, this is a sign she is refusing to submit and is not typically a good thing but could resolve itself if there isn’t further escalation.

It looks like things have calmed down as Klaus walks away and Ty Lee relaxes, but he turns back around to rumble strut one more time at Ty Lee, and Ty Lee decides to lunge at Klaus. Now Klaus assumes the lunging position and Ty Lee reciprocates.

They are now in the position you see screen grabbed below. This is very dangerous. If you see this yourself, your guinea pigs are angry and may seriously injure each other. You should intervene, but DON’T DO WHAT I DID, MAKE SURE YOUR HANDS ARE COVERED guinea pig teeth are sharp, long, and dirty and you do NOT want to be on the receiving end of an angry piggy.

After a brief standoff in this position, Ty Lee rumble struts at Klaus and slams her body into his, then lunges at his ear once more.

This leads to more posturing between them but Klaus doesn’t attack back yet, Klaus just rumble struts at Ty Lee as a way to say “back off or I’ll actually hurt you” but Ty Lee doesn’t listen. She lunges at him a third time. Big mistake. Klaus pays her back by lunging at her several times and starting an all out brawl between the two of them before I throw the towel on them to confuse them enough so they stop fighting.

Calming things down

Once they were out from under the towel, I could see that neither pig had any visible injuries so the whole brawl was just a series of nips. Klaus and Ty Lee tried to move towards the other but after being given food they lost interest in the fight so I allowed the bonding session to continue.

If something like that happened again, or I had seen any sign of injury from either pig, I would have stopped the session immediately. However, because I let it continue, every time Klaus postured at Ty Lee like that again, she submitted quickly. This kind of interaction is exactly why I wanted to write this post. Yes these pigs fought, but they still had a successful bonding session. Since this is a re-introduction I also have the benefit of knowing that Ty Lee and Klaus are some of the closest friends we have among our herd. I regularly see them engage in grooming behavior - a rarity with guinea pigs - and they frequently choose to bed down near each other. Interactions like this during bonding sessions are not an indication that your guinea pigs won’t get along long term, it only shows that they haven’t quite settled the pecking order yet, but they’ll get there. Ty Lee just needed to be reminded that if she wants to be in the herd, Klaus is in charge and she can’t be picking fights with the other sows.

You can watch the full video of the brawl below.

Examples of Normal Boar Dominance

Some other normal behaviors during bonding sessions are chasing, butt sniffing, and mounting. Particularly when you have a mixed-gender bonding session and any of the sows are in season (as I suspect Ty Lee was during this session), the mounting can be pretty intense at times. Once again, unless a serious fight breaks out, let it happen. Just make sure that as time goes on, things are calming down, not up..

Klaus chases Ty Lee and Mai, and rumbles at Vanya

Klaus steals food from Ty Lee

Klaus steals food from Mai

Klaus mounting Ty Lee

This example in particular is likely a dominance display, not mating behavior. Though - that happens as well.

Examples of Normal Sow Dominance

After this interaction, besides a few reminders from Klaus all of the sows deferred to him moving forward. However, the sows hadn’t settled things between each other. In particular, Ty Lee and Vanya were still battling it out for the top girl spot. While at the beginning Ty Lee got a few jabs in at Vanya, towards the end Vanya’s assertiveness has Ty Lee submitting to her more often than not.

It’s important to note, I don’t think Ty Lee and Vanya are friends. They tolerate each other for the sake of the herd, but as Vanya gets more into her senior years I am going to be watching for bullying between Ty Lee and her and if necessary we’ll need to separate them permanently. The main thing I was watching for in this bonding session is if they could play nice together again now that they’re both healthy. For now, I think the answer is yes.

Vanya chasing Ty Lee

Vanya ear nipping and chasing Mai for food stealing

Vanya butt licking

When we saw this behavior the first time we were rather confused. Guinea pigs are copraphagic meaning they eat their own feces as part of their normal diet. This behavior can be plain old dominance behavior, or could indicate a potential nutritional problem in the licker. In this instance it is likely a dominance display, but keep an eye out if you see this behavior from your pigs.

While we didn’t see it this time, it is not unusual to see mounting behavior between sows. It’s actually a little unusual NOT to see it, at least with our pigs, but they’ve also been introduced in the past and weren’t quite as aggresive this time.

Screaming does not necessarily indicate pain

As you might have guessed from the examples so far, Mai is our most submissive guinea pig and did not try to assert dominance on anyone at any point. Often times she just had a fear response to the other pigs and would freeze in place, which often didn’t work out for her as they ended up barreling into her and then doing dominance displays at her. Mai often responds to this with an ear-piercing and heart-wrenching squeal, it was really hard not to intervene when this happened but it’s important that we don’t. No one is getting hurt, this is part of them communicating. Her screaming is just her way of saying she is not a threat. Mai is just tired of the drama and wants everyone to get along.

Moving Forward

Once everything was mostly settled, we put them back in their cage with the divider removed and fresh bedding to remove any scent from their time apart. While this bonding session is finished, dominance displays are likely to continue among the sows for a few days or weeks until they settle into a routine. I’m especially watching for negative interactions between Ty Lee and Vanya, and listening for any chattering or whining that might tell me they haven’t completely made nice yet.

A few days later though, and while the buggers scatter in their cage as soon as a camera comes out, I’ve already witnessed the following events that might surprise you given the rather nasty interactions you saw in the rest of this post:

1. Ty Lee and Klaus bedding down together.
2. Vanya and Mai grazing at the hay feeder together.
3. Vanya and Ty Lee eating from the same food bowl - when others are available.
4. Mai nipping lightly at Vanya and Klaus on various occasions - indicating she’s comfortable pushing back and isn’t locked into her fear response anymore.

I’ve also seen Mai running her routine hot laps since we removed the divider. That divider unfortunately blocks the long end of the cage so they’ve not had the full area available for exercise for the past month. Mai is often joined by Ty Lee for a round of hot laps, and when she’s in the mood you can often see her running at Ty Lee or Vanya and playfully lunging at them almost like a puppy until one of them goes down to the lower portion of the cage and chases her. This is usually followed up by a lot of popcorning from both piggies. Ty Lee often indulges Mai in this behavior, but occasionally Vanya joins in for a lap or two as well.

All in all, re-introductions went well. Vanya and Ty Lee seem to interact much better now that they’re both healed up and I’m not concerned about any repeat fights at the moment. Klaus is very happy to have the two sows back, and Vanya is quite happy that Klaus can now bother someone else. And all of the piggies are happy that they can once again wander the entire length of the cage.