Younger rat aggressive towards rat with hindleg degenration! HELP!

Hey everyone,

I desperately need some advice. This is going to be a long post, as I want to give some background. Last year I adopted a lone female from the Durham Humane Society (Aria). She was in the smallest cage and very skittish. I had no expectations that she could be socialized, but I wished to give her a better life as I had the space and funds for a single critter nation.

I picked up a cagemate for her, whose previous owner could not keep her anymore (Harmony). She had been a lone rat, but was very social and friendly with humans. She ended up being lovely with Aria as well.

Nearly a year later, Aria still does not like to be picked up or held, and is skittish to pets. She will sometimes bite if my hand is in the cage cleaning, or adjusting things (unless your're offering food, lol). She hasn't bitten out of the cage, so I'm assuming she is just territorial. I do not have an issue with this, since every rat is different and some are just more aggressive than others.

Aria also likes to fight Harmony, who wants nothing to do with the fighting and will submit immediately. But Aria will still continue to nip at her. Personally, I have not found any bad bites or blood, and Harmony seemed to evade Aria pretty well most of the time.

But in the past few months, Harmony's hind-leg degeneration has been progressing, and her mobility is limited. In this time, Aria has gotten increasingly more aggressive with Harmony, even though Harmony will submit.

I added an extra shelf into the critter nation so there is less of a drop in case of a fall. I don't really understand why Harmony's loss of mobility is causing more aggression from Aria, but it is very concerning to me. I do not have the space to separate them, nor do I want to, as they'd be lone rats again if I did. However, they don't seem to enjoy each other's company.

I don't know if I can resolve this, or if I might have to give one away and pair the remaining one with another. But Harmony requires medication twice a day everyday and glucosamine. Aria is not very social and aggressive. So even if I went the route of rehoming one of them, it'd be hard to find a home.

Anyone else have similar experience? Any suggestions would be appreciated!

Unfortunately, some rats have been known to become slightly aggressive with handicapped and or aging rats. It's almost like they don't want a hurt rat in their environment which would make sense to a wild rat. It can attract predators. I'm hoping this is just a phase...but you may want to set up a time out cage. A time out cage should be extremely small and not have anything in it. No bedding, no food, no water. Each time you catch Aria being a bully, put her in the time out cage for about 10 minutes. Do this every time she's bullying Harmony. Hopefully this will help her stop the unwanted bullying. I sure hope it does work out, it would be a shame if you have to rehome one of them. They are both not ideal pets with their unique circumstances and not everyone is as understanding as you.

Sad that these things happen.

I definitely second the time out cage idea, as jorats mentioned.
What is your cage set up like right now?
Maybe if the cage is big enough, you could rearrange things a bit so that both rats have their 'own space'. Since Harmony has trouble moving around, it should be easy to create a high shelf that only Aria can access. It might not help since the aggression sounds more territory\dominance based, but it's worth a shot. Also, make sure that it is very easy for Harmony to get away if need be. Consider decluttering the cage a bit, escpecially in corners, and have nest boxes or houses with multiple exits.

I am wondering if adding a new rat to the mix might help? Perhaps it would distract Aria?

I've re-arranged the cage to be a bit more "minimalistic" and I'm now trying to use a small cat carrier as a time-out cage. I will see how this goes. I'm not sure space would be an issues, since the two share a single CN with an extra shelf (making 3 levels). I have noticed that Aria behaves very differently from any other rat I've owned (both towards humans and other rats), and I guess the behaviour is more "wild" than "pet". I've sometimes questioned if I've accidentally adopted a pet mouse or other rodent, lol.

I'm open to adding a rat, I would have to eventually anyway, as Harmony is older than Aria and is sick enough that she could take a bad turn any day, but I worry it could make things worse. Not sure if worse fights may erupt if the new rat will not submit to Aria, or if Aria will turn redirected aggression towards Harmony (not sure if rats do this, but cats do). Do you guys think it would be beneficial to add a rat?

It might help adding a buddy but it's definitely no guarantee. I would only recommend a buddy if you have space for a second cage and take the time for proper intros. But since you were thinking of adding a newbie eventually, it might be the right time for Aria. Ideally, you may want a rat that is more outgoing and bossy to give Aria a challenge.