Mouse cannibalism

Mouse cannabalism

If a mouse dies, others in the cage will often eat its remains – usually the brain first, but sometimes other parts too.

This is unpleasant to think about, and worse to see, but it is nature’s way and it does not mean that your mice are ‘nasty’.

Mice will not kill each other in order to cannibalize – they only cannibalize a mouse which has died somehow.

It’s highly unlikely that they would go through the danger of a fight to the death just to get food – this is unheard of, even when mice are starving.

Usually the mouse died of natural causes, but occasionally one will die after fighting. Note that this doesn’t mean that the fighting occurred because one mouse wanted to eat the other; the mice would have been fighting for other reasons.

Try not to be too upset if one of your mice is cannibalized after it dies. Mice don’t share some human social rules on these matters – they just see an unwanted body, which can be a valuable source of nutrients for them.

They are just doing what comes naturally.


  1. gsmonks on June 25 at 12:45 pm

    Mice and rats are cannibals, and a problem rat or mouse will kill others of its kind and eat them, and in some cases will eat them alive, usually starting with the head. I’ve witnessed this myself, and had to separate the offender from the others for their safety.

  2. Evilware on March 2 at 9:40 am

    Interesting article. My dad told me of the “Supermouse” theory. It states that scientists put several mice together in a barrel without food. The last one to survive after eating the rest of the mice would be free and transformed into this SuperMouse that changed its feeding habits by eating other mice. This would be used as a way of exterminating them. Have you heard about it??

  3. Chaz on December 5 at 8:16 pm

    This article is bogus. Mice will sometimes attack and eat other mice — even alive.

  4. Phoenix Borealis on December 14 at 10:52 am

    I had a pet mouse named Brother who cannibalized another mouse. Up until I learned that this is a natural occurrence, I blamed myself for not taking proper care of them. But after the same thing happened with my brother’s rats, I looked it up and learned that it happens quite commonly, and that made me feel much better. I got the mice as a result of my brother’s ball python refusing to eat them. I had Brother for about a year before he died of a fast-growing mammary tumor. I took very good care of him and saw no behavioral changes after the cannibalism occurred. In fact, I was able to fully socialize him, and he ended up being uncommonly friendly for a mouse.

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