I had two sisters I bought In Feb around 7 to 8 months old...ish. one sister got a tumor and it took her in abt a month after she started showing. The other got real depressed and wldnt come out of her hidey for days n days. I felt so bad so I went to buy her some friends abt 5-6 days later. Went to PetSmart. I know I know, I looked up breeders and rescue but nothing went in my favor and the soonest I could get one was at least 1.5 months. I bought 2 young female sisters. That was all they had. I followed all procedures I could muster up with Google. I love my rat but she's one mean bi***. In the bathtub after abt a week of switching things back n forth between cages, there is fur flying everywhere and she looks like a dog with a rag doll. Very vicious. Finnaly moved them out of the travel cage and closed off the DCN my oldest had to herself. Moved them in the bottom and they still find spots they can contact each other and she bites their fingers and makes them bleed. Won't let go. I've tried one other time a week or so later in the tub and it was the same deal. Shes so mean. Beyond the normal hierarchical shuffles rats have. Her sitting and biting their fingers is reinforcing the behavior but the only other option is 2 rats in a travel cage. I'm open to any thoughts. I'm starting to think I'm just gonna have a loner rat living adjacent to 2 sisters. At least she's not depressed anymore I guess. Not visibly at least. I'm open to any thoughts or ideas