You are here:

Mice/Cannibal mouse


Hi, I had two white male mice for nearly two years in a cage together. They ate and slept together. One died and the other had eaten her head???? Is this normal behavior?. They were well fed.

Hi Robert,

I am very sorry for your loss.  Mice cannibalize for a variety of reasons, but in this case it sounds like he was trying to get rid of the body.  Unfortunately, as gross as it seems, it is very common in rodents for eating other mice to start from the head down.  It is possible that this is out of mercy - if the mouse is still alive but dying, the other will have killed it before it continues eating, so he will not feel any more pain.  Another possibility is that it is simply the most efficient.  However you look at it - this is a very common occurrence, especially in male rodents, and serves to keep from wasting any nutrients in the natural environment.

Unfortunately, as natural or normal as it is, it can also make the survivor ill, so it is important that you keep an eye on his health in the coming week.  Not only can eating a mouse who died from unknown causes risk making the survivor sick, too, but he will also have a lowered immune system due to natural grief that he will experience at the loss of his buddy.  He will be relying on you more than usual for compassion and friendship, so try to give him a little extra time and watch him closely.  It would also be a good idea at this point to give the cage a good cleaning and sanitizing, since the cause of death for his friend was unknown.

Best wishes, and I am so sorry again to hear about your loss,


All Answers

Answers by Expert:

Ask Experts




I can answer questions regarding mice as pets, mouse behavior, color and coat genetics, breeding techniques, and general health questions. I can help with caging and setup, nutrition, social issues, and what to do in most mouse emergencies (such as unplanned litters, injuries, fighting, etc.). I can also assist with questions pertaining to orphaned mouse pups, weaning litters, and questions of mating and birthing. I cannot answer questions about exotic or wild varieties of mice such as spiny or pygmy mice. *****FOR EMERGENCIES, anything requiring immediate medical intervention, PLEASE take your mouse to a professional veterinarian or wildlife rehabilitator who works with mice as soon as possible! IMPORTANT RESOURCES: Raising Orphaned Mice: Orphaned Mice Videos: Natasha's Your First Mouse: General Mouse Help: Mouse Info and Exotic Breeds:


I have enjoyed the companionship of mice nonstop since 2004, and spent a year caring for them in a lab where I learned a great deal about their breeding, social needs, and health. I spent a few years breeding them, specifically working with albinos, marked mice, angora mice, and satins. My education never stopped - I am learning something new every day from current and well-established research thanks to the wonderful folks at the Jackson Laboratory, as well as from my wonderful mousey friends online. I also love learning from my terrific questioners here on AllExperts - you folks keep my passion for these amazing animals alive and well!

East Coast Mouse Association - expired, American Fancy Rat and Mouse Association - expired

Partial University for a B.S. in Microbiology, Partial University for a 2-year degree in Veterinary Technology (RVT cert), C.E. classes in pathogens, aseptic technique, genetics, and applications

©2016 All rights reserved.