This guide covers domestic fancy mice, Mus musculus, rather than wild mice or other small rodent species. Choose compatible companions and prepare their enclosure before adoption.
Company needs careful planning
Compatible females are usually the straightforward group option. Male housing needs an individual plan: familiar brothers may coexist, but this is not a guarantee, and unfamiliar adult males must not simply be placed together. Ask a mouse-experienced rescue or vet about a lone male, introductions and whether neutering with compatible female company is appropriate. Mixed sexes otherwise risk unwanted litters.
Secure space with good air flow
For two mice, Blue Cross recommends at least 80 × 50 cm of floor space and 50 cm height. More space may be needed for larger groups. A well-ventilated wire cage with a solid tray floor supports climbing and burrowing; bar gaps should be no more than 6 mm. Keep it indoors, away from draughts, direct heat and other pets.
Add a deep layer of low-dust paper or card bedding, several nest boxes and shredded paper for nesting. Avoid fluffy cotton-like nesting material. Provide tunnels, safe climbing structures, things to chew and a solid-surface wheel that allows a straight back.
Food, water and cleaning
Use a balanced mouse-specific food; complete pellets prevent picking out only favourite ingredients. Offer small suitable fresh-food portions within the normal allowance and scatter some food for foraging. Maintain constant clean water and check its supply every day.
Remove soiled bedding regularly. When a fuller clean is needed, retain a little dry, unsoiled familiar bedding rather than stripping away every scent.
Handling and health
Let mice approach gradually. Scoop with cupped hands, support the whole body and hold close to a safe surface; do not lift by the tail. Changes in eating, breathing, weight, skin or normal activity need prompt veterinary advice.
Sources checked
Guide copy checked on 2026-11-08. This is a source-based editorial review, not independent veterinary review.