As most of you know by now I've recently adopted two new cats. I already knew that both of my girls probably wouldn't like my new additions but I never thought it would go this far. A few nights ago I heard a rucus in my second bedroom which is now a cat room. Pear had cornered Colby and she was aggressively attacking him. I was able to break it up and poor Colby hid under the bed for a long time. Now at least once a day, I've noticed that Pearl will start chasing Colby and attacking him and she usually ends up cornering him so he can't escape. I already have comfort zone plugins going in three different rooms and both Pearl and Ziggy were wearing calming collars for a while but they didn't work and the collars made them lose their appetite too which I though was weird. Even my vet told me that the calming collars just don't work. Most of the time Pearl stays in my bedroom so I don't have to worry but when I feed the cats everyone is out in the main area except for Alani & Blaze who are later fed in the bathroom. I won't ever let Pearl be around Colby or Finnegan now when I'm not here. What else can I do? I just don't know why she has to be so aggressive towards him, he's such a sweet boy.