What cage for a pet mouse? The bar spacing trap to avoid
The pet mouse is the smallest common pet rodent, and also the most escape-savvy: bar spacing designed for a hamster leaves it plenty of room to slip through. Find all our guides in the bedding and habitat category for rodents.
What bar spacing is actually safe?
A maximum of 0.8 cm between bars is needed to stop an adult mouse from squeezing through, compared with the roughly 1 cm generally tolerated for a Syrian hamster. Many cages sold as "hamster cages" in pet shops go well beyond that limit and aren't suitable for a mouse as they come, a gap we also cover in our guide on choosing a cage for a hamster.
How much floor space should you plan for?
Budget at least 0.3 m² of floor space for a small group of females (adult males don't cohabit with each other), spread across several levels connected by ramps rather than vertical bars, which are harder for such small feet to climb.
What setup should you build around the cage?
- Paper or cardboard to shred for nesting material: mice are compulsive builders, unlike some other rodents that use far less material.
- Several hideouts spread across the different levels, never just one for the whole group, to avoid tension.
- A solid wheel (never a bar-style one, dangerous for the tail) sized to its small frame, on the same principle as for other rodents, as covered in our comparison of exercise wheels versus saucers.
Wire cage or tank: which should you choose?
A well-ventilated tank, with mesh covering a good portion of the lid, removes any risk of escape and cuts down on bedding scattered outside the enclosure, at the cost of ventilation you need to watch more closely than with a standard cage. Either way, avoid fluffy synthetic bedding as nesting material, a common trap covered in our article on why fluffy cotton nesting is dangerous for rodents.
Frequently asked questions
Can you house a male and a female together?
No, unless you're deliberately planning to breed: the pair reproduces very quickly, much faster than hamsters or gerbils.
How many mice can you house in one cage?
A small group of three to five females generally cohabits well given enough space, as long as you provide plenty of hideouts.
Does a mouse need a wheel like a hamster does?
Yes, its nighttime activity is intense: a wheel sized to its body remains one of the best forms of enrichment you can offer it.
This guide is part of Planète Pets’s Rodents universe. Our advice is general in nature: for any health concern, your veterinarian remains the only reference.