We have a male cat that was kept in a room for the first six months of his life. This happened before we got him. By the time we did get him he was already extremely aggressive, but we hoped that with time he would calm down. Well, he's not. He is intent on running off any other cat, which is a problem since we have 3 females. He is far stronger than the rest and pretty much just terrorizes any cat in sight. In fact, the reason I moved Little Tyke down to my office was a real fear that Jack might kill her before she could fend for herself. We were lucky he never seriously injured her. It is sad because he is extremely affectionate with people. He could be a great pet. But I don't trust him. From what I have read, his personality suggests that he was damaged by his early confinement. The only option I've seen is the Feliway synthetic hormone, which is available in collar form now. We're going to try it but I don't have a lot of hope. It is going to take a big change in his behavior if we are to have peace in the house. Any other suggestions? If this doesn't work we're going to have to get rid of him. We've never been forced to consider this option before.