Well I posted about it in another thread, but here is a pic of my poor little babies that have lost their hair.
http://sarah.digeratihost.com/images/mice.jpg
They are in with 2 older hoppers, so Becky thinks the older ones are over-grooming the younger two. So I'm going to seperate them and see if that helps.
http://sarah.digeratihost.com/images/mice1.jpg