Our cat, Molly, will have kittens if she just eats and eats and eats. Then her tummy will get really big and she will have kittens. This is how it all works according to Bethany. Note: This also applies to humans. As I have been informed, if I eat and eat and eat, then my tummy will get bigger and bigger, until I have to go to the hospital and have a baby.
I have to admit, at this point, I think this is a great conclusion for a 4 year old and won't be disputing it! ;)