Mouse Housing
Size
The size of the cage you will need depends on how many mice you will keep together. For a pair or small group of females, a 2 foot square cage is ample space. Mice will appreciate a cage with multiple levels as they do like to climb, and it should be fairly tall.
Type of Cage
Aquariums
Will need a tight fitting mesh lid and lots of furnishing supplied for climbing and playing. It is also important to remember that ammonia and other fumes will build up faster in an aquarium or plastic sided cage than in a wire cage. However, as long as the lid is tight fitting they are pretty much escape proof, and have the added advantage of allowing a deep layer of bedding that the mice cannot spread all over your floor.
Wire cages
They provide lots of climbing opportunity on the sides of the cage, and it is easier to fix furnishings, platforms and toys to the sides of the cage. The most important thing is to make sure the bars are not too narrowly spaced so that the mice can escape (or get stuck trying to escape) and that the doors are placed to allow easy access to the entire cage for when you need to catch the mice. Wire cages marketed for mice are generally quite small, so larger hamster cages or even bird cages are preferable, but ideally the bar spacing should be 1/4 inch. Do not underestimate how small of a space a mouse can squeeze through (one of my girls, Phoebe, could quite easily break out of a cage with 1/2 inch spaced bars). Avoid using cages with wire mesh floors - solid flooring is a lot easier on the mice's feet. The modular plastic cages meant for hamsters are actually well suited to the mouse size and activity level, but are difficult to clean, are sometimes poorly ventilated, and a determined mouse could chew right through the plastic.
Click here for some cage ideas
Placement of the Cage
The cage should be placed where the mice will have lots of human contact to make taming easier. It should be out of drafts, away from direct sunlight and out of reach of other household pets.
Bedding
A deep layer of aspen shavings or some other suitable substrate should be provided in the cage. Avoid cedar and pine shavings due to the strong volatile oils released form these woods (especially cedar). Aspen or other hardwood shavings appear to be a better choice. Another alternative is paper or wood based cat litter - it is very absorbent and good at controlling odors. It is more expensive but you will likely use less. In addition, nesting material should be provided. Strips of facial tissue or soft paper towel will be happily be shredded by mice and makes nice nesting material. I don't usually recommend the commercial cotton bedding material you can buy because some has strands that can get caught on the mice's feet. Hay can also be used.
Click here for some safe bedding ideas
Nest box
A nest box should be provided, and can be store bought or homemade. Small cardboard boxes are fine, although they will be shredded over time and need to be replaced fairly frequently. Clay flower pots, either with holes cut in them or placed on their sides can also be used, as can PVC plumbing pieces you can find at the hardware store. The nest material should be cleaned out only every month or two as needed (more frequent changes may be too disruptive).
Wheel
A solid surface wheel is easier on their feet than wire wheels. Their tails of feet could slip through and break.Click here for some safe wheels
Tunnels
Also provide some tunnels or tubes (plastic plumbing pipes sections or paper towel or toilet paper tubes).
Water Bowl and Food Bowl
For water, a gravity fed water bottle with a dispenser is preferred as it can't tip and keeps the water clean. A shallow food bowl of ceramic or porcelain is the best choice as they are difficult to tip, won't get chewed up, and they are easy to clean.