My dad is of the belief that you put as many eggs under a hen that will fit. Well, me being too dumb to listen to myself, about NOT listening to his advice, put 15 eggs under a medium sized hen. She just hatched, and she only hatched 6. 6 didn't have anything in them, and the other 3 are in the bator, hopefully going to. So I was wondering, what is a good number of eggs to set under small or medium hens?