I've had this happen with hamsters before but I never knew mice were cannibals. Are they eating the babies too or just killing them? My brood hamster would eat their heads and leave the little pinkie bodies behind.
She probably had 3-4 litters before she kicked it. Ironically enough, her last litter returned the love and I had to bury what was left of her in the backyard.

gag. so nasty.

I have always had better luck keeping rats vs. mice. But the best and easiest ever were the guinea pigs. I think it would be hard to feed them out though. They are every so friendly and pop out hairy and squeeking. I've seen them frozen some places that sell frozen gerbils too. I wonder if my BP would take them......