My cat had kittens a month ago...?

Every time they run around and play she starts to meow like crazy... Why?
She is a good mother, she is anxious that the babies are going to get into something.Mother cats can be overprotective just like people.Her kittens are getting at the creeping stage now, starting to get into things and play.It is just her reaction to want to keep them all together, so she can keep an eye on them.Also, they are a strain, nursing kittens at that age.They are growing so fast now, it is taking more and more milk to feed them.Give her a can of food when she starts meowing and she will calm down.
its her own way of protecting the babies, you will need to give it some time before you can play with them. the cats scent is the only thing the mom wants on her babies.
It sounds like she