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Pet Rats/Aggressive Rat During Free-Range Time


QUESTION: A couple of weeks ago, we were going to let our males from both cages play together, which we had done in the past with absolutely no problems or aggression from either side. One of my boys, Pippin, snapped faster than the eye could see and went from acting normal to literally trying to kill the males from the other cage. At the price of having my finger gashed open, I intercepted the fight quickly and there were minimal injuries. I told my husband, Jake, that Pippin is about that age. He is just now like 8 to 8 1/2 months old, precisely the time when males tend to become aggressive, so I have heard. He's never been aggressive to his cage mates or people.

He poofs up his fur and a little while afterwards begins acting defensive around his cage mates when we sit him in the floor of the bedroom for free range time. I am assuming it's because he smells that those other males have been there. We scoop him up and sit him on the bed, where they have not been -- and his fur instantly goes down and he goes back to being sweet old Pippin. It is really frustrating, because I want him to get to play.

We live in a one bedroom apartment, it's not like I can rat proof two different rooms just because of him. It is so maddening. I'm just like "Chill out, they aren't here!" Also, I wouldn't mind maybe trying to clean the floor in between, but we have carpet so I doubt it would be feasible to try to get rid of their scent every single day.

I may eventually have him neutered, when we have our previous rat vet bills paid off. In the meantime, is there anything I can do?

ANSWER: Hi Elizabeth, I am so sorry if you didn't receive my response to your question.  I answered about a week ago but I think something must have gone wrong with this website because now it's informing me I never answered you.

So here goes again.  I am not surprised that Pippin's aggression began at this are correct about the male hormones escalating, often at an even earlier age.  If you ever want him to live with the boys from the other cage, or at minimum act "civil" towards them, a neuter is a must.  Some rats, like human males, have a higher level of male hormones than others, and he is one of them much to your misfortune.

In the meantime, it doesn't sound like there is much you can do about their shared play area.  One thought is to perhaps purchase 2 (or more) very large inexpensive sheets or something similar to cover all or most of the floor of your bedroom.  Lay one sheet out when Pippin and his cagemates are playing, then switch to the other sheet when the boys from the other cage are freeranging.  Another alternative might be to use a bathroom for one group of boys and your bedroom for the other group.  True the bathroom is probably small, but you can make it feel bigger by loading it up with lots of playthings, such as stacking bunches of empty boxes, throwing in a bunch of old towels, sheets, socks, whatever you can think of.  Their exploring area may be small horizontally, but you can make it huge vertically if you use your imagination.  Rats don't necessarily need a lot of square footage, just as long as they have many stimulating things to explore and discover.  Old junk can keep them busy for long periods of time :)

Ask if your vet (or perhaps call around to find another) will allow you to pay for the neuter in installments.  Some vets will work with you when you have a hardship.

Out of curiosity, may I ask why you keep two sets of males in separate cages and not all in one large cage?

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QUESTION: I did not think that my cages were big enough for them all to live comfortably. At the time they were all friendly with one another, I had three boys in a cage with a max capacity of four and four boys in a cage with a max capacity of four. I also had a baby in one group, so I thought it would be best to wait until we got a DCN.

Now that we have upgraded, I can't introduce them. Looks like I will be calling the vet. Once we get our last bill paid off on our CareCredit, Pippy is gonna have to go.

That same kind of cage situation is why I have two separate groups of girls as well. I want to introduce them but I have never done group introductions, really. There is a group of five and a group of four. We have two DCNs, and I'd like the boys to share an entire cage and the girls to as well -- that way they can have access to a bigger environment with more toys and friends. I have two sisters who are a bit ornery, but other than them, I don't see there being much of a problem. If it wasn't for Lucy and Trouble.. Lucy tends to automatically dislike new rats, and Trouble tends to start acting up as well if Lucy does.

Oh I understand now...thanks for the explanation.  I hope that my suggestions about playtime were helpful.  Otherwise I guess after the surgery you can hopefully successfully into Pippin to the others (of course it's about a 3 week wait after surgery for all the hormones to leave his system). Please let me know if there is anything else I can help with.

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Irene Murphy


I can answer a variety of questions regarding adoption and care of pet rats throughout their lifetimes, including questions about their health and well being, temperment, diet, bedding, cages, toys, etc. I will try to answer your questions to the best of my ability in a timely manner and I have an abundant amount of resources to help me to help you with your pet rats. I love rattie pictures, so include pics with your question if you can. You may ask me medical questions, but please be advised that I am not a vet. I may use my resources to answer some medical questions, however, I will need to refer you to your local vet with medical questions that I feel I am not qualified to address.


I have been a huge rat enthusiast for many years. Since becoming a rat owner, I have educated myself in all areas of pet rats from every resource I could find including the internet, books, conversations with local exotic vets, as well as several local rat breeders.

I have a college degree but not in the area of animals. I have obtained my extensive experience and knowlege of pet rats all on my own because in my eyes, pet rats are the most interesting and fascinating creatures you can ever imagine to have as pets. I also am saddened by how mislabeled and misunderstood these amazing and extremely smart animals are by the majority, and my mission in life has become to educate and change as many people's perceptions of rats as I possibly can.

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