My youngest make has to be caged because he wants to always fight with the other two boys. They were all fine until Mikey reached three months or so , now he won't get along. He is absolutely great with people . Help with advice PLEASE
He puffs up and rears , with his mouth open showing teeth. He has tore the ear of other rat.How exactly is he acting? Defensive rearing up with mouth open when an older male approaches? Or does he lower his head, scuttle sideways, fur puffed up, rubbing with paws, chattering teeth (I put in all the behaviors just in case, you usually don't see all this early at 3 months).
Have there been any injuries and if so, where and how bad?