Mice eating each other!

I was about to go do laundry when i saw that my feeder mice were eating another mouse. Why would this happen? I have pics if necessary :X

Check your water bottle to make sure it's not clogged.

my mom had that happen to her when she was little. mabye it was just hungry for meat

Usually they will cannibalize each other only when dead. Could the mouse have passed away and you didn't notice? Either that or like the other have stated, check the water bottle. They will also cannibalize each other to get re-hydrated.

Water bottle is fine. Could the mouse of died... possibly. It has been the mouse i have been trying to feed to my snake the past few days.

There are two main reasons for canibalization.

One, is if you have two or more males together. They will kill and eat each other until there is only one left quite often.
Another, is extreme stress. How are your mice set-up?

my mice are in a big plastic tub with lots of wood shavings.