The most commonly available type of mouse available as a pet is the domestic pet mouse. These pet mice have been selectively bred to enhance the desirable qualities of the mice. There are also spiny mice (which are desert creatures that are a bit trickier to care for), but for the purposes of this article we will discuss the ordinary domestic mouse.
Ordinary does not mean boring, however. If you have ever seen a group of pet mice playing, you realize they can be quite entertaining pets. They are a bit skittish and harder to handle than some of the lager rodents such as rats, but they can become quite tame and will take food from the hand and allow themselves to be handled if started at a yound age. Mice are quite ideal as small pets that are entertaining to watch, are easy to care for and make very few demands on their owners.
Their short life span is one of the biggest drawbacks of mice. On average they live for about 1.5-2 years, although they can sometimes live up to 3 years.
Mice are nocturnal and very social. They will be very active in the evening and night, but don't expect to do much with them during the day. Being social, they are best kept in groups. A pair of females is the easiest, although larger groups are fine if you provide the cage space. Pairs of males should be avoided, unless they are litter mates, never separated, and given a large enough cage that they can have their own space (unfamiliar males are very likely to fight). Keeping males and females together should be avoided unless you want lots of mice in a short amount of time.
Choosing Healthy Mice
When picking out your mice, look for active bright mice, with smooth clean coats and pink clean skin on the ears and tail. The eyes and nose should be free of discharge, and the mouth and anal areas should be clean and dry. Their breathing will be relatively fast, but should not be labored or noisy. Check the cage as well - it should be clean (the mice have been well cared for) and the droppings should be formed.
Look for a pet store that separates males and females at a young age (good breeders will do this). Mice can reproduce by about 6-8 weeks of age, although this is very stressful on the female and should be avoided. If your pet store doen't separate mice at a young age you may well end up taking home a pregnant female. To tell the difference between young males and females check under their tails for the distance between the anal opening and genital opening - this distance is shorter in the females. A breeder or pet store should be able to do this for you, but it can be hard to do in young mice unless you have males and females to compare to each other. In older (6-8 week old) male mice, the testicles are usually readily visible.
Next: Cages for Pet Mice