The =Wood Mouse=, or =Long-tailed Field Mouse= (_M. sylvaticus_). Back a brown shade of yellowish grey; belly white, sharply marked off; relatively very long hind legs, hence a hopping gait. The long-tailed field mouse penetrates tolerably far into woods, but is also found in plantations and gardens, sometimes also in quite treeless regions. On arable land it may adopt the habits of the field vole (p. 42), but as it does not multiply so rapidly is not nearly so injurious. It may also live either for a short time or permanently in houses, adopting the same habits as the common mouse. The =Harvest Mouse= (_M. minutus_). Small, pretty; back yellowish brown red, belly of a sharply marked-off white. Lives in cornfields during the summer; in harvest time by the field-paths; during winter in barns and haystacks, but also in outdoor nests in the fields. Climbs among the grass and corn-haulms, and the small stems and branches of other plants, including shrubs, holding fast, not only by the feet, but also by the tail. Builds a beautiful spherical nest with a side entrance out of the haulms and leaves of grass and corn, or out of other leaves. Devours seeds, especially grain, oats being the favourite. The =Corn Mouse= (_M. agrarius_). Back brownish red with longitudinal black stripes. In plains east of the Rhine. Usually local, but then very abundant. Chiefly in cornfields and fruitfields; digs holes in the soil. In autumn it often occurs in the field in large colonies. Food: grain, beans, peas, potatoes, turnips, carrots. In winter in the barns and dwelling-houses of farmers. [Illustration: FIG. 23.—Upper Back Teeth of Brown Rat, seen from grinding surface. ] [Illustration: FIG. 24.—Upper Back Teeth of Water Vole, seen from grinding surface. ] Regarding the means of destroying those mice which are sometimes damaging to agriculture (_M. sylvaticus_ and _M. minutus_), see methods mentioned under “Field-vole” (p. 43). Family: =Arvicolidæ= (_Vole Family_). The large voles are also popularly called “rats,” the smaller ones “mice.” They closely resemble the true mice and rats (p. 38), but are distinguished from them by their plumper, more compressed body; a thicker head with blunt snout, and ears quite hidden in the fur; and a short, tolerably hairy tail, on which no rings of scales can be distinguished. There are on each side of each jaw three back teeth, of which each appears to consist of two rows of three-sided prisms, fused together along the middle line (cp. Figs. 24 and 23). The native species all belong to the genus _Arvicola_; the Bank Vole (_Arvicola glareolus_), the Water Rat, or Water Vole (_A. amphibius_), and the Short-tailed Field Mouse, or Field Vole (_A. agrestis_). The brownish-red =Bank Vole= (_A. glareolus_) occurs in forests.