Should I replace her?

I had a group of mice together and the agouti female got pregnant right around the time the other female was already giving birth. Well she had her litter sometime last night or this morning and she killed all the babies. I'm not sure how many there were because she literally left them in pieces. Some pinkies had their heads chewed off, some had paws chewed off, etc. She was fine around the other female's litter when they were born. I'm not sure why she would destroy her own litter like this. They have plenty of water (I check the sipper every time I refresh their water) and they had tons of food. I wasn't messing with them yesterday or this morning other than refreshing water.

Reasons can be diverse

Food and or water issue, stress, first time mom, bad mom, etc.

Personally with my colony you kill your babies you meet with a snake. ;)

I would give her a second chance and if it happens again, she becomes a feeder.

I'd feed her off. I have a zero tolerance policy for canibalistic mothers.

I had one do that and she became snake food!! Same goes for the ASF female who ate her babies and could not keep a litter alive for more than 4 days she how ever got 2 chances!

I've had females kill and eat their young before but I've never seen a mother mutilate the pinkies in such a way. She ate the paws off of almost all of them, ate their tails and chewed them in half, or chewed their heads off. :( Given that she took so long to become pregnant in the first place, I might feed her off and just replace her. The other female is a great mom.

You said you had a group together. Are they still together? If so, how do you know it was the mother that killed off the babies?

You are raising up some females from your previous litter, right? They will probably be good breeders for you. In my experience, if you feel you need new blood, bring in males. The females seem to reproduce MUCH better in the environment they were raised in.

Well the "group" was a 1.2 and I needed the male for another group so the two girls have been together with one female's litter. Well they were both pregnant after this litter was born and now that this litter is approaching 3 weeks, I've been watching for pinkies. The agouti female is the one that dropped her litter (the black self is still pregnant) and mutilated them. I will be bringing in more breeders soon so feeding her off might be a good idea. And it was just my luck. The black self's litter that is approaching 3 weeks, she had 5, and only 1 was female. :rolleyes: