Sometimes kitties will get a little too rough! I usually grab them with the other hand (the one not being attacked...haha) by the nap/scruff of the neck and give them a gentle shake from side to side while saying "NO"! Mother cats and dogs do this to their young ... so it won't hurt him ... but hopefully he will get the message! If not, just keep putting him in another room ... so he'll associate seclusion with misbehavior! GOOD LUCK!