Dr. Mark is a veterinarian with over 40 years of experience in the field. He works with dogs, cats, exotics, and livestock.
My Rats Keep Fighting—What Do I Do?
"I decided to get my older rat (Ramsey) a friend and made the mistake of putting the younger rat (Powder) directly into Ramsey's cage. After some research, I followed the correct introduction procedure and they seemed to be getting along reasonably well.
Ramsey would sometimes forcefully try to dominate Powder and the squeaking would immediately make me want to separate them. However, the tiffs were short and no one was seriously injured.
After a few weeks of them getting along with little to no fighting, I cleaned Ramsey's cage, as it's the largest, and re-arranged the cage completely before introducing both rats to their new home. The first few hours were perfect—they even slept next to one another. However as the evening drew around, there was some squabbling and I'm unsure if I should separate them or let them settle.
Ramsey seems to be trying to bully Powder into submission, as Powder won't allow Ramsey to pin and groom her, but still hides underneath her and follows her around and wags her tail when Ramsey allows contact. —Cara
Rats Have a Natural Hierarchy
At this point, I would let them stay together and not separate them again. It sounds very much like Ramsey is the dominant rat and they have already worked out their hierarchy. The behavior you describe sounds very much like dominance behavior and not bullying.
If you notice that Ramsey is pulling Powder's hair, biting so much that he is drawing blood, or hissing at Ramsey, you will want to separate them and start over using the glove technique or a neutral meeting area.
In the Future, Introduce New Rats More Slowly
When Ramsey does pass on and you get another companion for Powder, be sure to introduce them slowly to prevent problems. Have a second cage on hand so that you can quarantine the new rat before introducing them to Powder (the article linked above has more information about quarantining a new rat).
This article is not meant to substitute for diagnosis, prognosis, treatment, prescription, or formal and individualized advice from your veterinarian. Animals exhibiting signs and symptoms of distress should be seen by a veterinarian immediately.
© 2022 Mark dos Anjos DVM