Mouse ate other mouse

Question
A few years ago I saved a white mouse from a snake. (my friends snake got full after the first 3 and she was just wondering the snakes cage, blind) She lived in a 10 gallon tank and was pretty happy. Got lots of exercise, food and etc. After a year or 2 I got her a "friend"....another saved mouse (black instead of white) but not as young as she was when I first got her. She was smaller then her but I am sure it was the same breed. (not sure which breed but the social breeds that are kept together alot). I frequently saw my white mouse groom the black mouse and they slept together but then a few days after putting them together I found the black mouse in the corner with no head. My white mouse ATE the whole head.

Why did my mouse do this? She seemed to like the black mouse. The black mouse wasn't nervous around the white one and they seemed to get along. I never heard them fight.

The white mouse has been gone for awhile...she died at around age 3-4. I never got her another "friend" after that incident with the black mouse.

but it has always been curious to me why she ate the black one.
any ideas?

Answer
Dear Ashley,

When one mouse dies, the other mice know instinctively to eat the body because in the wild the body can rot and foul the nest, making the other mice sick, and it can attract predators.  Your little black mouse most almost definitely died of a natural cause, and the white mouse just did what mice do.

I hope this puts your mind at rest!

squeaks,

Natasha