We have a cat that 2 weeks ago had a litter of two very healthy kittens. For the past several days the mother will go on crying for hours on end as if she wants something and we do not know what it is. She can go out whenever she wants, has all the food and water she wants. The one thing we can do to calm her down is to rub her stomach, but when we stop she will ususally go on crying again. Anyone have any ideas?