It is an excellent climber, and sometimes enters the upper windows of houses. It is more nocturnal in its habits than the Common Shrew; but is subject to the same autumnal mortality. It does not appear to construct burrows, but utilises those of Mice. Its nests have been found in various situations, such as a clump of rushes, a hollow tree stump or a hollow in the ground roofed by a stone; and they have been of different materials according with the local conditions, moss, dry grass, fine rush shreds and wood chips variously combined and interwoven to form a hollow ball. There are probably two litters of from two to eight young, born between May and September. *Water Shrew* (_Neomys fodiens_, Schreber). The Water Shrew is our largest species, the length of head and body combined varying from three to three and three-quarter inches, the body of bulkier build than that of the Common Shrew, and the tail longer than the body. Its upper parts are dark coloured--from slaty black to dark brown--and the light ashy grey or dirty white of the under parts appear pure white by contrast. The snout is shorter and broader than that of the Common Shrew; the small eyes are blue, and the ears, which are entirely concealed, bear a tuft of white hairs. The brown feet are broader and the digits are bordered with stiff hairs which make them more efficient as paddles; and the tapering flattened tail of the adult has a double fringe of strong silver-grey hairs along its underside, constituting a "keel" and making it more efficient as a rudder. The hind foot usually exceeds three-quarters of an inch. The fur is finer and thicker than in the other British Shrews; and the upper and lower colour areas are sharply separated one from the other. Its aquatic habits have in some districts caused it to be known as Otter-Shrew. The tail is brown above and lighter below. Variation to full black is frequent, and albinos have been recorded. The teeth have coloured tips like those of the other Shrews, but the points of the incisors are more hooked than in the two species of _Sorex_; moreover, there are two teeth less, the dental formula standing thus:--_i 3/1, c 1/1, p 2/1, m 3/3 = 30_. It is these differences in the teeth that has led to the Water Shrew being placed in a separate genus. [Illustration: *Skeleton of Water Shrew.*]