Water Vole (Arvicola amphibia), Fig. 17, commonly called Water Rat, and often confounded with the brown rat, which frequents the same localities, is a native of Britain, inhabiting the banks of streams, ponds and lakes. It attains a length of 13 in. including the tail of about one-third of the measurement, which is short when compared with that of the brown rat and mouse. The ears are very short and rounded, the soles of the feet hairless, and the head broad and blunt. Its colour is chestnut-brown, tinged with grey above, and fading into grey on the under parts. It breeds twice yearly, producing five or six young at a birth.

The Water Vole.

Fig. 17. - The Water Vole.

The water vole damages embankments by tunnelling below the level of the water, and often strays to places away from streams, devastating potato and vegetable crops, and in woods injures young trees by biting through roots up to 2 or even 3 in. in diameter when forming its runs. It appears to have a partiality to poplar, willow and apple trees. Otherwise it feeds on aquatic plants, its food being almost, if not entirely, vegetable, the carnivorous propensities reported against it being very doubtful. A black variety is common in some localities, particularly in the north of England and north-east of Scotland.