Cat quesiton

Question
I have a important cat question!

My cat had kittens and the kittens are now five weeks old. Once in a while when the mother is cleaning the kittens or for no reason at all she will pin down the kittens one at a time at different times and start biting them and the kittens start to cry. It looks like she is biting them hard. Is this normal as in a way of dicipline or is it something else.

Answer
I'm not sure if this is dicipline or if the mother cat is rebelling or something, the only thing you can really do is keep an eye on the kittens, catch the mother doing this a scold her.  That may help but don't hit her just say a firm loud NO! and then stop the behavior