i know a few ppl that breed as well as i am and i dont have a problem with mice or rats eating the babies. i dont separate the males rats will eat the babies that they cant take care of or there is something wrong with them(some wont eat them period). mice on the other hand will eat them to control the population somewhat, but not as bad as my asfs do. ive noticed that sometimes if you have rats weening and pinks in the same tub sometimes the weenlings will eat the pinks.