Harvest mice are the smallest rodents in Europe. Their body length is only 5-8 centimeters, plus a 5-centimeter long tail. They live in tall grass, brushwood, dike vegetation, undergrowth, grain and reed fields. They are good climbers, avoiding the ground as much as possible. Nests are made by splitting live blades of grass and rubbing them into a kind of ball. Harvest mice are mostly active at night. They eat seeds, berries, fruit and shoots of grass, as well as mushrooms, moss, plant roots and insects.