Try to play with a rat or mouse before you buy one, just to make sure you will not have to find another home for him because you have an allergic reaction to him. These small mammals frequently bother people.
For their small size, rats and mice need a lot of exercise. Each one requires at least 2’x1’x1’ of space, and a two-story cage with a ladder between floors is most enjoyable for them. Glass or plastic housing is usually best, or a metal cage with a removable tray-bottom for easy cleaning. Make sure the cage is away from drafts. Rats and mice prefer a segregated sleeping area, so build a 5”x5” box for them, or simply add a pint-size glass jar placed on its side.
Give them lots of bedding. You will find they use one corner of the cage as a bathroom. Since rats and mice urinate frequently, you should pile the shavings or sawdust especially high in this area. Give them plenty of clean straw or hay so they can make comfortable nests.
You should change the bedding every few days, and completely wash and disinfect the cage once a week. While you are cleaning the cage, move the rats or mice into a large box in which you have placed tree branches. Your pets will enjoy a good play session, and be out of your way.
Contrary to popular opinion, cheese is not good for mice. Neither is meat. Rats and mice do very well on a diet of rodent cow or pellets, with occasional treats of fresh fruits and vegetables. Unless you notice your pets getting particularly fat, feed them as much chow as you want. Rats and mice should always have plenty of fresh water available at all times. You should also make sure they have some wood – either a piece of hardwood or some twigs – to gnaw.
To remain tame, rats and mice need frequent and gentle handling. Never pick up a small rodent by the tip of his tail – you might skin him. Hold him by the base of the tail and slip your other hand under his hindquarters. Always treat your pet gently and patiently. If he seems to panic when you first lift him, hold him by the base of the tail until he calms down. When handling your rat or mouse, never make any sudden downward motion – this will give him a bad fright.
Rats and mice are inquisitive, active creatures. Make sure they have an interesting and varied environment, and give them lots of toys. They are especially fond of exercise wheels, and ladders and branches to climb. A small rodent needs these additions to his cage to be a happy and healthy pet.