How many times a week do you have to clean mice bedding for two mice, and roughly how big does a cage need to be for two mice?
The minimum size cage I use for any of my mice is about 10 by 12 inches (120 square inches) for a small, single, male mouse. The cage must be large enough for a comfortable igloo or other sleeping space, a second hiding space (a small box or half of a cardboard egg box work well), a wheel, a food bowl and a water bottle. Mice are also quite active and need some running space between these objects. How often you clean it depends on how many mice are living in it, the sex of the mice and the type of litter.
First, male mice should live alone as they are very territorial and won’t tolerate another male in their cage. A single, male mouse should have its bedding cleaned weekly if you are using hardwood shavings, other types of bedding may need to be cleaned more often depending on how well they control odor.
Be careful about changing bedding too often for a male; males are territorial and they will “mark” their territory with urine. Every time you change a male mouse’s bedding, it needs to re-scent the area, and if you change the bedding too often it can encourage excessive nervous marking and make the mouse smell even worse. Strong-smelling litters can cause the same reaction.
If your male mouse’s cage is a little smelly after a few days, scoop out his bathroom corner and replace the soiled litter in just that area, most males are not disturbed by this, and it doesn’t usually trigger excessive marking.
Female mice have much less odor to their urine than male mice; they are also very social animals and enjoy lots of female companionship. I typically house my girls in groups of 3 to 10. I adjust their cage size and the number of sleeping spaces to suit their needs. A group of three girls usually only need the bedding to be cleaned weekly, but larger groups usually have to have the bathroom corner changed at least once a day.