Hi All, I am experiencing some redirected aggression from my female cat. here's the situation: Mavis, 1.3 yrs old, female, adopted 1 yr ago. She is the queen Kevin, 1.2 yrs old male, adopted 2 weeks after Mavis. I had planned to introduce them slowly, as suggested by most cat behaviour sites I visited, but Mavis refused to let that happen. Lucky for me, Kevin is a chill dude, and was adopted from a house of 17 cats and knew his place, so it took maybe a week for them to get along. Or rather, for Mavis to accept Kevin. Since then: they play together, groom each other, and I think love each other and are truly brother and sister at this point. All was well, until my aunt's cat, the same age, came into my care due to illness, and no one else wanting to take responsibility for her. Again, I wanted to introduce them the right way, and had Izzy, female, 1.3 yrs old and very shy and timid, staying apart and unseen in the basement while I swapped scents. Well of course it didn't take long for Kevin and Mavis to realize what was going on in the basement. Kevin, Mr. Cool, was crouched down at the door, chirping at Izzy, and trying to figure out what was going on. Never upset, just genuinely curious. The problem is with Mavis. She would sit at the door and hiss and growl occasionally, which is expected, nothing I hadn't experienced with her with her introduction to Kevin. The problem I have is that now she is turning on Kevin. Whenever he makes an attempt to "talk" to Izzy, Mavis hisses at him, and now their play ends quickly with Mavis hissing. This is devastating for me, because I don't want to destroy their relationship! Poor Kevin just looks bewildered when this happens. I could handle Mavis being angry with Izzy, I can slowly introduce them and see what happens. But I don't know what to do with this redirected aggression, because all blogs and articles I read say to remove the stimulus. Well I can't really do that right now. I know the obvious answer is to find Izzy a new home, and I might still end up having to do that, but I'd really like to keep her, if I can. Any thoughts? Ideas? Feliway never worked with the Mavis to Kevin introduction, so not really sure how well it will work now.