The harvest mouse is Europe’s smallest rodent. Its body and tail are roughly equal in length, between 5 and 7.5 centimetres, and it weighs just 4 grams. Its fur is predominantly yellow to rusty brown, and whitish underneath.
It is typically found in wet meadows covered with tall grasses, other wetland vegetation, and cereal cropland at low elevations throughout most of Europe and temperate Asia.
Active both day and night, the harvest mouse climbs well, using its prehensile tail as a fifth limb. It builds oval-shaped nests from available vegetation. During the summer, the nests are perched among reeds, sticks or branches; during the winter, the nests are situated on the ground or in burrows. The harvest mouse feeds on seeds, berries, buds and insects. It hibernates during the winter.