Cages for hamsters should be at least 19 x 19 inches square and 6 inches high. The best cages have a solid base; do NOT use a cage with a wire mesh floor, as this can injure the hamster's feet. There are generally three types of cages: wire mesh, glass, and plastic.
Wire cages have the advantage of allowing the hamster to use the wire itself as a way to have climbing exercise. The horizontal bars should be 1/2 to 3/4 inch apart. Ideal wire cages have a detachable base for easy cleaning.
Glass cages (aquarium tanks) have the advantage of being easily cleaned, but have poor ventilation and do not in themselves provide a way to exercise.
Plastic cages are commercially available with multiple built in tunnels and toys, but are generally the hardest of the cages to clean. In addition, ventilation is less than optimum.
Hamsters like to burrow, so bedding should be deep. Good choices of bedding include recycled paper pellets and wood shavings (NOT cedar). The bedding should be changed weekly. Most hamsters use one corner of their cage as a toilet area, and this area may need to be cleaned more frequently.
Hamsters are permissive hibernators, meaning they may become less active when the temperature dips below 60ºF. As the temperature further decreases, hamsters will curl-up, slow their breathing, enter a deep sleep, and barely move at all other than an occasional whisker twitch. This hibernation can sometimes be mistaken for death. Owners must be cautious when bringing a hamster out of hibernation. As hibernation involves physiological changes, do not attempt to awaken a hamster by handling or elevating the temperature markedly. Instead, raise the temperature by 5 degrees every six or eight hours until the temperature returns to about 68-75ºF. Keep in mind that hamsters can be stressed by high temperatures, too, so keep the animals in a cool part of the house during summer months.
Hamsters prefer to have a nesting house where they can sleep undisturbed during the day. Provide nesting material such as facial tissue, soft paper towels, commercial cotton bedding or other soft materials. The nesting material should be cleaned out every 4-6 weeks; cleaning more often may stress the hamster. Since hamsters may bury food in the nesting material, it should be checked routinely, and any hoarded food removed.
Toys and exercise
Hamsters love to chew and burrow, so this will give you clues as to what toys and exercise accessories will be most appropriate. An untreated piece of 4x4 works well. Drilling large holes through the wood will provide tunnels, as well. They also like to play with and chew cardboard tubes from toilet paper and paper toweling. Larger cardboard boxes can also be good toys, but like the tubes, they will not last long and you will need to replace them often. Special chew toys are also available from pet supply companies.
Almost all hamsters will use a hamster wheel which should be at least 5½ inches in diameter. Unfortunately, they use the wheel at night and a squeaky wheel has kept many a hamster owner awake for hours. A little mineral oil on the axle will help. PVC pipe and commercially available tunnels can also provide good exercise.