killing mice

Question
I have a mom and 4 babies. The babies are 1 month old. Last night the mom ate half of one baby and killed another. When I saw this I seperated them at once. Can you tell me what happened.They are all healty. Thanks

Answer
Dear William,

There are three possibilities.  If the baby died by itself, the mother has the instinct to eat the body so it doesn't foul the nest.  A mother mouse can also get confused and kill the babies if she thinks they are in danger.  However, that is less likely at a month old. And of course, maybe she is simply an aggressive mouse.  You were right to separate them just in case, and you should not try to put them back together.  

I'm so sorry about the tragedy.

squeaks,

Natasha