HAMSTER, a European mammal of the order Rodentia, Cricetus cricetus belonging to the mouse tribe, Muridae, in which it typifies the sub-family Cricetinae. (See RODENTIA.) The ham sters are short-tailed rodents, with large cheek-pouches; the largest is the common C. cricetus. Their geographical distribution com prises Europe and Central Asia. Most of the European hamsters show more or less black on the under-parts, but the small species from Greece and Central Asia (Cricetulus) are uniformly grey. The common species constructs elaborate burrows containing sev eral chambers, one of which is employed as a granary, and filled with corn for winter use. As a rule, the males, females, and young of the first year occupy separate burrows. During the winter these animals retire to their burrows, awakening about February or March. They are very prolific, the female producing several litters in the year, each consisting of over a dozen blind young; and these, when three weeks old, are turned out to form underground homes for themselves. The burrow of the adult descends 4 or 5 ft. beneath the surface; on retiring for the winter the hamster closes the entrances. Although feeding chiefly on roots, fruits and grain, it eats small quadrupeds, lizards and birds. It is fierce and pugnacious, the males fighting for possession of the females. Their numbers are kept in check by foxes, dogs, cats and pole cats. The skin of the hamster is of some value, and its flesh is used as food. America, especially North America, is the home of the majority of Cricetinae. They are divided into about two dozen genera and the number of species is very large indeed. Both in size and form considerable variability is displayed; the majority of the species are, however, mouse-like, as in the genera Peromyscus (white-footed mice) and Oryzomys (rice-rats). The subfamily also contains the American Grasshopper Mice Ony cliornys, and Harvest Mice (Reithrodontornys). The Florida cotton-rat (Sigmodon hispidus) is another representative of the group. In the Old World the subfamily is represented by about six genera, three of which Cricetulus, Cricetus, and Mesocrice tus) are European, and one (Mystrornys) is African.