So my rat Winn started displaying some very aggressive behaviors towards me and his 3 cage mates right after i adopted 3 babies. I have 7 rats now all males, 4 adults (all about 7-8 months) and 3 babies (almost 3 m/o). The adults and babies were kept in separate cages and i have introduced them slowly with a lot of success. I would allow the adults to go into the baby cage, and then allow the babies in the adult cage, I scent swapped, and the two groups could constantly smell each other. Winn has shown 0 aggression towards the babies when i let him in the baby cage, and when the babies were in the adult cage. He has only been aggressive to me and his cage mates. Constantly picking fights with his cage mates (he goes out of his way to perform aggressive displays to his cage mates and chases them when they try to get away) and he even bit me 3 times in the month I've had the babies. Twice when I tried to pick him up, once when i was cleaning. All three times drawing blood, two of which were very deep. After the first two bites i stopped trying to pick him up, respected his space, and it seemed to work for about 2 weeks. This past week and a half he's been picking less fights with his cage mates, though he still picked a few fights some of which i had to separate. Each time he's started fights for the last 2 weeks I've kenneled him for 5 minutes, and then opened the kennel for him to go back into the cage on command. (he's trained to kennel and go back into the cage both on command). After each time out he calms down for several hours or even for the whole day without picking fights. But the fact that he was fighting as often as he was and that he was showing aggression towards me made me come to the conclusion that he needed to be neutered. I just got him neutered yesterday (Tuesday the 10th), because i thought it would better his quality of life, his cage mates lives, and make it easier for me not to have to deal with an aggressive rat . And then today when trying to give him his pain meds he bit me the 3rd time very hard drawing blood. I hadnt even tried administering the meds, i just went to pick him up. I know he's cranky today, in pain, probably mad to be isolated and in a small space (to prevent movement), but how long on average does it take for male aggression to go down after neutering? I know it varies from rat to rat, but I guess i'm asking for people's personal experiences neutering aggressive rats. Was it successful? How long did it take for the aggression to go down? I just want to get an idea of what to expect in the coming weeks with him.