Dwarf hamster may refer to any of a number of hamster species whose members are of diminutive size. These miniature species belong to the genus Phodopus or Cricetulus. They are often favored as pets, though some hamsters still live in the wild. Due to their small size and affinity for specific environments, dwarf hamsters are unusually frail. Their environment must be carefully maintained in order for the hamsters to enjoy a long life in captivity.
There are ten species between the two genera that fit the dwarf hamster classification. They all originate from dry or semi-arid climates throughout Eurasia and Asia. Roborovski's hamster is found in the Gobi Desert, while Campbell’s dwarf hamster resides in dry mountainous areas, like the Altay mountains of Mongolia.
The lifespan of most dwarf hamster species is short. Some species, such as the winter white Russian dwarf hamster and Campbell’s hamster, live around two and a half years at the most. Other miniature species, like Roborovski's, live up to four years in captivity. The average lifespan of all species tends to increase in captivity, as exposure to predators and other threats is limited. The lifespan also changes based on other environmental factors.
While the hamsters' sizes can differ according to their environment, no dwarf hamster species has been known to reach the same length as a regular-sized hamster, even in captivity. Roborovski's hamster is the smallest species known to exist and, on average, reaches only 1.5 inches (3.81 cm) in length when fully matured, with rare cases approaching 3 inches (7.5 cm). The Chinese dwarf hamster averages 3 inches (7.5 cm) to 3.5 inches (9 cm) and can weigh between .9 ounces (25 grams) and 1.5 ounces (43 grams).
Dwarf hamster care is similar to that of other small mammals. Owners often provide the hamster with bedding through which it can burrow, as its natural instinct is to dig, along with some tubing for it to climb in and out. The tubing should not be too large, or the hamster will find itself unable to safely climb out of it. Wood bedding other than cedar or pine is recommended as absorbent, dust free, and safe for the fragile respiratory system of dwarf hamsters. The temperature should remain constant, and food should always be available, as the hamster will eat a lot and often.