Why Do Mice Stink?

Mice are highly social animals, and they use scent as a way of communicating, identifying other members of their group, establishing territory and determining the reproductive status of females. Male mice will scent mark and produce more odor than their female counterparts. Male mice paired together may compete with each other, even if there are no females present, and scent mark their favorite corners of the cage to establish dominance over other mice. If you only have one male mouse as a pet, he might still mark in his cage, particularly if he feels insecure. Each mouse has his own particular smell, and some mice are just smellier than others.

If you are cleaning out your mouse's cage every day, you could be adding to the odor problem. When you scrub and disinfect his cage too often, you're removing the comforting odors that make your mouse feel secure. Putting him back into his cage will send his scent marking instincts into overdrive, and you may find his cage smells particularly strong the days after a vigorous cleaning. Try to limit a complete cage cleaning to once every five to seven days. When you do clean his cage, leave a familiar toy or toilet paper tube untouched, and place it back into the cleaned cage. The toy will have his scent and might make him feel less stressed. Try and keep his nest intact, too. Mice seldom soil in their sleeping area, so it should be quite clean.

If your mouse's cage is too small, the odor may build up more quickly and soon become unpleasant. Contrary to popular belief, mice are clean animals and may prefer to soil in a few select places in a cage, rather than all over. If his cage is too small, he may be limited in the places he can use as a toilet, and the odor will seem strong in a matter of days. You might be tempted to put your mouse in a glass tank, rather than a wire cage, thinking this will eliminate smells. But tanks don't allow for healthy ventilation, so ammonia levels will build up, causing harm to your mouse's respiratory system.

You may not be able to completely eliminate your mouse's odor, but there are some things you can do to co-exist happily with your little buddy. Once a week, empty all the bedding out, and wash and disinfect the cage's pan. Use a safe and absorbent bedding made out of recycled paper. Some mouse owners use corn-cob bedding, which is slightly more expensive but which can help neutralize the ammonia in the cage. Pet stores also sell special liquid deodorizers, which you can add to your mouse's water. These can also be expensive, but some owners have success with cutting down odors by using these. You can buy an air purifier or use room deodorizers, but avoid aerosol deodorizers, as these can harm your mouse's delicate airways.