Merck Manual

Please confirm that you are a health care professional

honeypot link
Pet Owner Version

Providing a Home for Mice


Katherine E. Quesenberry

, DVM, MPH, DABVP (Avian);

Thomas M. Donnelly

, BVSc, DVP, DACLAM, DABVP(ECM), The Kenneth S Warren Institute

Reviewed/Revised Jun 2020 | Modified Oct 2022

Your mice will be healthier and live longer if you provide them with appropriate, well-ventilated housing, a nutritionally sound diet, and opportunity to exercise and explore their environment. Good sanitation is the key to preventing many types of disease.


Various cages are available to keep mice. In general, a cage should have good ventilation, be easy to clean, and be escape-proof. The cage floor should be solid; wire mesh or grid flooring can damage the feet and legs of mice. Cages made of wood are unacceptable for mice because their urine will soak into the wood. This causes ammonia buildup, which can lead to respiratory disease. Mice may also chew through the wood, allowing them to escape.

Cages must have wire mesh on the top for good ventilation. The wire should be fine enough to prevent escape and strong enough to resist chewing from adult mice. A mesh with squares measuring 1 cm or less is recommended. The minimum cage size for 2 to 3 mice is 18 inches (45 cm) long by 18 inches (45 cm) wide by 10 inches (25 cm) high. The bedding and floor covering should be absorbent. Wood shavings or prepared litter can provide soft bedding for mice. Cedar or pine shavings should be avoided as they may irritate the mouse’s respiratory system. Hay or recycled paper may be added. Mice are nest builders and will make nests from their bedding for sleeping.

Fresh water should be available at all times to prevent dehydration. A water bottle with a hanger that allows mice to easily access the water is recommended. Holders with chew guards for the water bottle are available. These allow you to hang the bottle inside the cage. A water dish or bowl should be used only in emergencies because mice often will spill the water or push shavings in it. If you use a food dish, it should be easy to clean and sturdy enough to prevent tipping.

Poor environmental quality, such as high ammonia levels and poor-quality bedding materials, can increase the risk of bacterial or viral infections in mice. Cages should be cleaned with hot water at least once a week and the bedding should be changed at least twice weekly. Fresh water and food should be provided daily. All dishes and water bottles should be thoroughly cleaned before refilling.


Mice need a balanced diet that includes carbohydrates, fat, and protein. Commercial mouse diets contain all the vitamins and minerals mice need and are also hard enough to wear down their constantly growing incisor teeth. Pelleted diets formulated for pet mice should be supplemented with fresh vegetables and small amounts of sunflower seeds and fruit. On average, an adult mouse will eat 3 to 5 g of food and will drink 3 to 5 mL of water daily. Pet mice should have food available at all times. Fresh food can be provided once a day (at night); uneaten food should be removed. It is normal for mice to eat their own fecal pellets.


Routine exercise is necessary for good health in all animals. Mice are extremely active and enjoy opportunities to exercise and play. Access to exercise wheels, tubes, ladders, and climbing blocks will fulfill this need. The cage should be large enough to accommodate some of these cage toys and allow comfortable movement around them.


Mice are very social animals, and they appreciate being in a group. However, male mice tend to fight unless they grew up together. Unrelated female mice can normally be placed in the same cage without any problems.

Usually, mice are good pets for children. However, they should be kept away from other pets in the house such as dogs, cats, birds, and other rodents. Remember, mice are the natural prey for several of these animals!

Because mice are nocturnal, they can be quite active at night. You may want to consider placing the cage in a location where sleeping family members will not be disturbed by their activity.

For More Information

quiz link

Test your knowledge

Take a Quiz!