Why is my cat acting this way?

[Sammy-San]

My cat is about a year and a half old-and female. My sister just brought over a kitten who is about a month old. She's a very small animal, who is staying with my family until we find somebody who wants to adopt her. Even though she's a female cat, we call her Charlie. Charlie is very playful and friendly towards us, and even towards izzy-my cat. But Izzy starts growling and making wierd noises and hisses whenever she sees the kitten. She runs away from her.

I dont get this. Is she territorial, or afraid of the new cat? I dont understand. The new kitten is so tiny, I dont understand why she would be either one towards her. Izzy likes my moms friends little dog, but she hates this kitten, who is even smaller. Why is that?

Even more bizzare, Izzy HATES my sister. Whenever my sister goes near her or pets her, she makes rumbling noises and hisses at her. Could it be she holds a grudge against her since she sees her bringing the cat to this house every day? None of my previous pets acted as bizzare as holding grudge against people.

 

[Bananagator]

Cats are very territorial creatures. Since these two cats are somewhat far apart in age and not from the same litter, it makes sense that there's some resentment. Years ago my family had two cats from different litters. Our first cat never liked the second one, hahahaha.

My guess would be that your sister probably smells like Charlie, which is why Izzy is being a little hostile.

 

[OceansDeep]

Get some catnip they will put aside there differences for some catnap.

 

[Guru03]

If cats are of the same gender, it's going to end badly.

If one of the cats has an aloof personality or is a breed known for having an aloof personality (towards other cats or animals), that will be a problem.

My 7 year old Maine Coon has an aloof personality towards other animals and hates all other animals except herself so I feel your frustration.