Female kittens together while in heat

Question
Hello, I have two kittens both female, one is spayed and the other is not. The younger kitten just went into heat for the first time. The old spayed kitten appears to be aggressive with her all of a sudden. Is this normal? Is it safe to have them together? Does the spayed kitten feel challenged in some way? should I separate them? Thank you for your help.

Answer
Hi
no i would say that the aggression is just a normal cat territory issue. Your spayed kitten is just trying to let the other kitten know that she still has certain territory rights, cats will do this every so often. The only time this may get worse is if the other cat does become pregnant and then their is likely to be fights for territory as cats don't want too much competition form other cats and kittens.
I wouldn't worry too much but just keep an eye on them just in case a spat turns nasty.

Kate