The Wood Mouse is sometimes known as the Long-tailed Field Mouse and is widespread, probably most common in woodland, rough grassland and gardens. Wood mice have dark brown fur on the back with a greyish-white underside. There is a clear straight line where the two colours meet. A mainly nocturnal species, it has protruding eyes and large ears. A tail as long as its body enables it to balance when climbing and jumping: the large hind feet assist with this.
Found throughout the British Isles, even on the smaller islands, the wood mouse is our most common and widespread wild rodent. It is an inhabitant mainly of woodland and fields but is highly adaptable and is found in most habitats if not too wet. It is rarely recorded on higher exposed ground with little cover. Wood mice are essentially nocturnal but some individuals may venture out in daylight.
Most wood mice live in underground burrows. The burrows are fairly complicated and may include nest chambers and food stores. Burrows probably survive from one generation to the next and will be enlarged or modified as required. Nests are commonly made of leaves, moss and grass. They are usually built below ground under the roots of shrubs or trees but occasionally are found in holes in trees, buildings and bird or dormouse nest boxes. Additional nesting material is used in autumn and winter; often the mouse blocks the entrance to the burrow with leaves, twigs or stones.