Kitten and no tail, what?.............!?

My cat had 4 kittens and their just about a week. Today I was holding one, like I have done many times before and but never noticed one didn't have a tail. There is a little little nub, but all the rest of the kittens have long tails. I don't no who the father is, but don't remember seeing any cats around without tails. Could the mommy cat ate it when they first came out, when she was cleaning the stuff off them? I just can't believe I never seen this till today, I thought I checked them all out when she had them and all the body parts were there. hmmmm.... as it gets bigger will it grow one? I know I sound stupid, just have no clue how I didn't notice this