Re: Cat aggression problem
Did you go through a formal introductions process between your cats and your parents cats? If not, I would recommend starting over. Google 'cat introduction' to get the idea and then go through the process of a complete separation, scent swapping, seeing each other thru a door cracked open a little bit etc.
Squirting and time outs are not going to work. She is doing what is instinctive, there is something about this cat she doesn't like. Is she getting along with your mom's other cat? If so, the other possibility is that the cat she is attacking sick in some way. It's instinctive to drive the weak members out so the entire colony is not at risk of a predator. A cat can know when another cat is sick way before symptoms appear to the humans. So a vet check and full blood panel for the victim might provide some info as well.
And yet another possibility is she is challenging this cat for position within the colony.
You might want to read Cat vs Cat by Pam Johnson Bennett, it will give you some good insight on how multi-cat household interact and she has a good section on cat introductions. I got my copy in Barnes & Noble, it's also available on Amazon.
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Holly, Misty & their friend, Jake, the dog.
Onyx, Callie May, Maggie & Kobi forever in my heart.
Yes, I know I need a new signature pic...someday...