Mice are social creatures and are happiest when living with another mouse, provided all animals are spayed or neutered, or are females only. Mice need at least 2 feet by 2 feet of floor space for up to five mice (a group of more than five may not get along), although the more space you can provide, the better. They also prefer cages with more than one level so they can climb. The taller the cage you can provide, the better.
The best cage for a mouse is made from wire that is no more than 1/4 inch apart. The floor should be deep and solid. Hamster cages often work well. Ferret cages also have more than one level, although be sure the wire is close enough together so the mouse can’t escape.
You can also house your mouse in a glass aquarium with a securely fitting mesh wire or screen top, although this enclosure offers less ventilation than a wire cage. If keeping your mouse in an aquarium, you’ll need to be diligent about removing soiled bedding every day.
Accessories for your mouse’s cage are important and should include a crock-style food bowl, a hanging water bottle, small nest box or flower pot, a solid-floored exercise wheel, tubes for tunneling, an unpainted and untreated piece of wood or safe chew toy, and places to climb, including swings, ropes and ladders.
Your mouse’s cage should be located on top of a table or dresser (never on the floor, where it’s drafty) in a room that is quiet. The room should have natural light, although no direct sunlight on the cage, which could cause the temperature to rise. Avoid placing the cage in the path of an air-conditioner or near a heat source. Do not keep the cage in a basement or garage, where dampness or fumes could harm your mouse. Mice can withstand cold temperatures easier than heat. Keep the room between 67 and 75 degrees Fahrenheit.
The best bedding for mice is paper-based litter sold for small animals. Mice also like shredded paper towels and tissues for building their nests.