Why Cats Eat Their Kittens?

Well I just found out that they do that well I found out that the reason cats eat their young is usually because their sick or deformed since mother cats have fully digestive guts so the sick don't harm her but she usually eats them I  mostly think is that mother cats don't want their kittens to suffer and also so that if they live outside is that if the mother eats the sick or deformed is that if the kitten dies the predators would smell the kittens out and eat them but usually the mother eats them and so that the case don't happen.

Almost any animal will eat their young if the young arent going to survivie

Young mother or premature birth, sometimes placenta does not separate properly and mother cat accidentally bites into it,harming the kitten, causing injury, so she eats it Also weak or ill kittens will be eaten.

Because they are ill and they know that they have some think Wong with them I think

I found my cat with a still born kitten a live kitten and sadly two heads, she had eaten them for whatever reason I am now hand rearing the  live kitten as the mother isn't interested.

I don't know myself, my cat ate her kittens as well yesterday and I don't know why -_-

As far as I knew it they didnt =S and ive had like 7 kittens before =/