My mouse gave birth to a large litter this morning and was observed eating one of her pups when I first saw them. Since mice often eat their sickly/stillborn babies I didn’t think much of it. Fast forward like six hours and there are 3 and a half (she’s eating another one now) left. I did not disturb the nest at all or even open the cage, and yet she’s still killing and eating them. The way she kills them, too... it’s way more brutal than even a live feeding (which I don’t do to begin with) and I’m honestly tempted to just humanely cull the remaining pinkies myself so they’re not slowly eaten alive. If she ends up eating all of them, it’ll be really hard for me not to instantly cull her too. I know I’m anthropomorphizing a mouse but I can’t unsee those babies squealing as their limbs were being eaten by their own mother.

The problem is that these are show-line mice, and I have a limited number (1.3) with none available to replace her at the moment. Since this was not environmental or nutritional, what are the odds she will kill a future litter? She is a first-time mom. I’ve heard infanticide can be a genetic behavior and if that’s likely to be the case, I’ll just CO2 her now and save myself the headache.