Cannibalism in adults (not mothers and babies)

Question
I took home this female fancy mouse from school that needed a home. Apparently she ate her two cage mates (both males?). I'm wondering if it's because she might be pregnant and didn't want the males to endanger her babies, or anything else. She was with the other two mice for at least half a year. Now she's sneezing and I'm wondering if maybe a stressful environment has something to do with it too? Please help me in any way possible! I can't find anything on adult mice eating other adults!

Answer
Dear Amber,

I can't be sure, but my guess is that each of the other two mice actually got sick and died. When a mouse dies, the other mice are afraid the body will rot and so they eat it to avoid the sickness that they could get from a rotting body.  So she felt she had to eat them.  

Now she is sick with what they had.  She should go to a vet to get treatment.

If a vet visit isn't an option, then you can treat her at home with an OTC antibiotic sold for fish called Tetracycline.  The vet can be more sure what she is sick with, and has more modern medicine, but this home remedy often takes care of the problem.  

I explain how to administer Tetracycline in the following archive post:

http://en.allexperts.com/q/Mice-3824/2008/11/Mouse-Respiratory-Infection.htm

When she is healthy, you can give her a new friend.  I can't guarantee, but I think it will be fine.  

Good luck!

squeaks,  

Natasha