The harvest mouse (Micromys minutus) is a small rodent native to Europe and Asia. It is typically found in fields of cereal crops, such as wheat and oats, in reed beds and in other tall ground vegetation, such as long grass and hedgerows. It has reddish-brown fur with white underparts and a naked, highly prehensile tail, which it uses for climbing. It is the smallest European rodent; an adult may weigh as little as . It eats chiefly seeds and insects, but also nectar and fruit. Breeding nests are spherical constructions carefully woven from grass and attached to stems well above the ground. History The genus Micromys most likely evolved in Asia and is closely related to the long-tailed climbing mouse (Vandeleuria) and the pencil-tailed tree mouse (Chiropodomys). Micromys first emerged in the fossil record in the late Pliocene, with Micromys minutus being recorded from the Early Pleistocene in Germany. They underwent a reduction in range during glacial periods, and were confined to areas in Europe that were free of ice. During the mid-Pleistocene, Micromys minutus specimens also lived in parts of Asia. This suggests that they spread towards Asia when the ice sheets started to melt. Other evidence suggests that Micromys minutus could have been introduced accidentally through agricultural activities during Neolithic times. Before the harvest mouse had been formally described, Gilbert White reported their nests in Selborne, Hampshire: They never enter into houses; are carried into ricks and barns with the sheaves; abound in harvest; and build their nests amidst the straws of the corn above the ground, and sometimes in thistles. They breed as many as eight at a litter, in a little round nest composed of the blades or grass or wheat. One of these nests I procured this autumn, most artificially platted, and composed of the blades of wheat; perfectly round, and about the size of a cricket-ball. It was so compact and well-filled, that it would roll across the table without being discomposed, though it contained eight little mice that were naked and blind. Tennis balls used in play at Wimbledon have been recycled to create artificial nests for harvest mice. Description The harvest mouse ranges from long, and its tail from long; it weighs from , or about half the weight of the house mouse (Mus musculus). Its eyes and ears are relatively large. It has a small nose, with short, stubble-like whiskers,