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Pet Rats/aggressive female rat


I have two girl rat. i bought scarlette at petco along with luna, luna became aggressive and tried to kill her so he took luna back and got terra. terra and scarlette have gotton along in there 2 foot by 1 foot cage for a month and a half and now all of a sudden scarlette is being mean she is biting terra and pulling on her skin everywhere really hard she sqeeks loud. It breaks my heart because terra is so sweet and so was scarlette! please help

As soon as you mentioned the size of your cage, it triggered a red flag.  That size cage is far far too small to house to adult rats.  Your cage is closer to hamster size.  A cage at least twice that size in either height or width should be provided for a better environment.  This could be one possible reason for aggression...they don't have enough space to be apart if they want to find solace.  Ideally, look for a cage that has 2 or even three levels and provide at least 3 places for them to "sleep", such as hammocks, igloos, tunnels.  You can put in empty boxes with holes cut out as sleeping or hiding spaces.  The more space there is the less likely your aggressive rat may fight the other.

Rats when babies will always play-fight.  When they become adults, they tend to do this less. If they've been together since babies, they will have become bonded.  However, and not too often, some rats when they reach adulthood may become aggressive toward their bonded cagemates.  This happens much more commonly with male rats but is not unheard of with females.  With males, neutering the aggressor often fixes the problem but spaying a female does not work this way.  

A third reason a rat may become aggressive to their cagemate is when she is ill.  Looks for signs of illness in your aggressive girl.  Is she eating, sleeping and playing normally?  Is she being aggressive at all towards you also?

Has the aggression appeared out of nowhere or come on slowing with aggression getting worse and worse daily?  Has blood ever been drawn during aggressive bouts?

My immediate recommendation is to look for signs of illness in the aggressor.  If you rule that out, then if the aggression is violent and/or if blood is being drawn, separate the 2 girls immediately until you find a much larger cage.  Dress up the cage with lots of hidey places and climbing toys, chew toys, etc.  Then intro the 2 girls into the big cage at the same time and monitor their behavior.  Hopefully, this larger space will solve the problems.

If it does not, read through some of the articles on this website about aggression in rats.  there is some good information on there.

Lastly, know that there are some rats that just will not get along with others (but may be fine with humans).  These rats must live solo.  They may also get along with a neutered male.  In that case, you might have to consider a more mellow female companion for your sweet Terra.

Please let me know if I can provide you with any other help.  Good luck to you and if you can, please do let me know down the road if your girls do start getting along again.

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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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