inbreed cats

Question
i have male and female cats plus kittens will they breed with each other

Answer
Yes. Absolutely. They don't have the social qualms like humans do regarding incest (which is the same as inbreeding), plus any nasty congenital (born with) disorders tend to pop up more often.

Needless to say, please cut down the number of cats, or please try to get them neutered. There are several low-cost clinics and cat rescue groups that can help you with the cost of neutering.