We've just started having an issue with our small female cat (Hallie) going after and bullying the older, bigger cat Casey. He's only a year older than her, but twice as big. It started with a major rumble a few nights ago - she was looking out the back door at something in the dark, he came up behind her with the intention of chasing her (he likes to do it, she doesn't) and I think he just really frightened her. She went after him with a vengence and it took two of us and a blanket to seperate them so I could get Casey upstairs and the door shut. He spent the night upstairs with us - usually they're stay downstairs with the doors shut at night. He was quite shaken and frightened by her reaction and it took quite a while to calm him down. The next morning they acted just as normal. So far so good we thought, but tonight she had another unprovoked go at him, only not quite as serious. Any ideas anyone can give to help us sort it out would be so appreciated! I've had the Feliway Friends diffuser on for 3 days now - maybe it's just going to take a bit longer. We could sure use some help if anyone has any ideas. Thanks folks - you always have good advice!