I have four cats. A pair of 4 year old brothers and a pair of 2 year old sisters.
Three of them get one very well, all sleep snuggled up together, lick each other etc. one of the girls never is with the othes (whilst the three are snuggled up somewhere she is downstairs on her own) but she has always been like that.
Lately though she has been more aggressive, swipes the other cats, hisses at them, sits on a chair and when they go underneath claws them.
I was wondering if she is just miserable, or of this is normal, and what I need to do about it. She is a jolly cuddly cat (naughty, typical tortoiseshell) but I don't want to be miserable. And I feel sorry for the others when she goes for them.