live in reed beds where they will weave ball-shaped nests above ground if no suitable banks exist in which to burrow. Water voles prefer lush riparian vegetation which provides important cover to conceal animals when they are above ground adjacent to the water body. Areas of heavily grazed and trampled riparian habitats are generally avoided. Water voles may be displaced by the introduction of riparian woodland and scrub as they prefer more open wetland habitats away from tree cover. As well as frequenting typical lowland wetland habitats dominated by rank marginal aquatic vegetation, water voles are also just as at home in areas upland 'peatland' vegetation where they utilize suitable small ditches, rivers, and lochs surrounded by moorland up to 1,000 m asl (e.g., northern Scotland). In Europe and Russia, they may venture into woods, fields, and gardens. They live under the snow during the winter. Water voles are currently being reintroduced as a threatened species in Yorkshire, England. In the Massif Central area of France, however, farmers are campaigning for action to be taken against water voles, where plagues of these rodents are causing major damage to crops. Diet Water voles mainly eat grass and other vegetation near the water, but will also consume fruits, bulbs, twigs, buds, and roots when given the opportunity. In Europe, rich harvest periods can cause water vole "plagues" to take place, during which the voles eat ravenously, destroying entire fields of grass and leaving the fields full of burrows. Water voles in some parts of England have been shown to occasionally prey on frogs and tadpoles; it has been speculated that this is to make up for a protein deficiency in the voles' diet. Food remains alone are not a reliable indicator of the presence of this species, as other smaller voles can also leave remains of large grasses and rushes. Breeding The mating period lasts from March into late autumn. The female vole's pregnancy lasts for approximately 21 days. Up to 8 baby voles can be born, each weighing around . The young voles open their eyes three days after their birth. They are half the size of a full grown water vole by the time they are weaned. Behaviour Water voles are expert swimmers and divers. They do not usually live in large groups. Adult water voles each have their own territories, which they mark with fecal latrines located either near