Hey guys, I have 3 RBP's in a 55 g. I got the 2 bigger ones about a week ago and they are finally getting used to the new environment. However, the biggest one seems to be picking on the smallest one. He hasnt bitten him yet, only swims really fast at him, and sometimes head-butts him in the side. I know it sounds funny but thats the only way I can think of to describe it. I dont think it's territorial, because all 3 P's seem to hang around the same place in the tank. Is this normal behavior, or something I should be worried about? What can I do to stop this? Oh, by the way I keep them well fed, and I had a large goldfish in there to balance out the aggression, but they never touched the goldfish.