Hey everyone,I'm looking for some feedback regarding introducing a new rat to my two older boys. Fenton and Bastien are brothers and are just shy of six months old. Tavey is about two and a half months old.Bastien took really well to Tavey. There is the occasional wrestling match, however most of the time they can be found snuggled up together. The whole introduction took about 48 hours. Fenton had to be separated from the cage as he bit Bastien's ear. The vet suggested removing him from the cage until Bastien's ear heals. This is very atypical for Fenton. The day that it happened Bastien and Fenton had had zero contact with Tavey. Anyways, whenever Fenton comes into contact with Tavey, he puffs up and attacks. I'm wondering if anyone has any ideas as to how to go about this. I've tried switching items in the cages to get them used to the smell of each other. I've tried reinforcing with treats but then I've noticed Fenton becomes food possessive and the aggression escalates. When I intervene, Fenton is good about not biting me. So at least I'm able to get in between if I need to. I've also put the two cages right beside each other. I'm at a loss.