The wood mouse, scientifically known as Apodemus sylvaticus, is a common and widely distributed small mammal across Europe and parts of northwestern Africa. This adaptable rodent frequently inhabits both natural environments and areas closer to human settlements, such as gardens and parks. Its secretive habits often make its presence unnoticed. The species thrives in various settings by adapting to available resources and conditions.
Physical Characteristics and Identification
Wood mice have a distinctive appearance. Their fur ranges from sandy-brown to reddish-brown on the back, providing camouflage. This dorsal color sharply contrasts with their pale or white underside. They have proportionally large, prominent black eyes and noticeable ears, which are larger than those of a common house mouse.
A distinguishing feature is their long tail, typically measuring 70 to 145 millimeters, which is generally the same length as its head and body combined. This tail is moderately hairy. Unlike house mice, wood mice do not emit a strong, musty odor, and their overall body size is slightly larger, with adults weighing around 23 to 25 grams.
Natural Habitat and Behavior
Wood mice prefer diverse natural habitats, including broadleaf and mixed woodlands, grasslands, and hedgerows. They also adapt to suburban environments like gardens and parks. These rodents are primarily nocturnal, active under the cover of darkness to avoid predators.
They are agile, capable runners, climbers, and even competent swimmers. Wood mice construct underground burrow systems, typically around 8 to 18 centimeters below the surface, which serve as havens for nesting and shelter. These burrows often feature multiple entrances and can include tunnels created by other animals. During severe winter conditions, wood mice may enter a state of torpor, a temporary reduction in physiological activity, to conserve energy when food is scarce.
Diet and Food Hoarding
The diet of wood mice is omnivorous, primarily consisting of plant matter. They consume seeds from various trees like oak and beech, along with berries, fruits, fungi, roots, and small invertebrates like snails and insects, particularly when seeds are less abundant.
Wood mice are known for food hoarding. They gather seeds and nuts, especially in the autumn, and transport them back to their underground burrows. These chambers act as larders to sustain them through the leaner winter months. This hoarding also contributes to seed dispersal, as some forgotten caches may germinate, aiding in plant regeneration.
Interactions with Humans
Wood mice occasionally enter human dwellings, typically in colder months when seeking warmth and food sources. Their flexible skeletons allow them to squeeze through surprisingly small openings, sometimes as narrow as a dime-sized gap. Once inside, they may establish nests in secluded areas like sheds, attics, or within wall voids.
Signs of their presence include small, dark droppings resembling grains of rice, found in cupboards or along baseboards. Gnaw marks on food packaging, wooden structures, or electrical wires also indicate their activity, as they constantly gnaw to wear down their continuously growing incisors. Wood mice are potential carriers of pathogens, including hantavirus. They may also transmit bacteria like Salmonella and Leptospira, or the lymphocytic choriomeningitis virus. Transmission can occur through contact with their droppings, urine, or saliva, or indirectly via parasites like ticks and fleas they may carry.