Hamsters are rodents belonging to the subfamily Cricetinae. The subfamily contains about 18 species, classified in six or seven genera.

The name hamster is derived from the German word Hamster, itself from earlier OHG hamustro, from ORuss choměstorǔ, which is either a blend of the root of Russ khomiak "hamster" and a Baltic word (cf. Lith staras "hamster")Doublas Harper, The Online Etymology Dictionary, s.v. "hamster" (2001) <http://www.etymonline.com>. or of Iranian origin (cf. Av hamaēstar "oppressor")Merriam-Webster's Collegiate Dictionary, s.v. "hamster" (May 29, 2008) <http://http://www.merriam-webster.com/dictionary/hamster>..

Behavior can vary depending on their environment, genetics, and interaction with people. Because they are easy to breed in captivity, hamsters are often used as lab animals in more economically developed countries. Recently hamsters have also become established as popular small family pets.

Hamsters are crepuscular. In the wild, they burrow underground in the daylight to avoid being caught by predators. They are most active around dusk and dawn, which has led many people to mistake them for being nocturnal. Their diet contains a variety of foods, including dried food, berries, nuts, fresh fruits and vegetables. In the wild they will eat any wheat, nuts and small bits of fruit and vegetables that they might find lying around on the ground, and will occasionally eat small insects such as small crickets or mealworms. They have elongated fur-lined pouches on both sides of their heads which extend to their shoulders, which they stuff full of food to be brought back to the colony or to be eaten later.

Characteristics

Hamsters are stout-bodied, with tails much shorter than body length and have small furry ears, short stocky legs, and wide feet. Their thick, silky fur, which can be long or short, can be black, grey, white, brown, buff, yellow, "sapphire" or red depending on the species, or a mix of any of those colors. The Djungarian hamster (Phodopus campbelli) and the striped dwarf hamster (Cricetulus barabensis) have a dark stripe down the middle of the back. Dwarf desert hamsters (genus Phodopus) are the smallest, with bodies 5 to 10 cm (about 2 to 4 inches) long; the largest is the common hamster (Cricetus cricetus), measuring up to 34 cm (about 13 inches) long, not including a short tail of up to 4 cm (1-1/2 inches). and the Angora hamster the second largest hamster breed, measures up to 15 cm (about 6 inches) long. The tail is often difficult to see; usually it is not very long, and on a long haired hamster it is barely visible. Hamsters are very flexible; and their bones are somewhat fragile.