Harvest mice are one of the smallest mammals in Estonia. They grow up to 6–7 cm in length; their tail is 5–7 cm long. Their tail, which is relatively tall for their body, has its function – it helps them grip and keep balance while climbing in bushes or on plant stalks. Their hair is brown. The back is dominantly brown, but their chest and stomach are slightly lighter. They build their nests from stalks and always locate it at least one metre above the ground. The nest is spherical and about the size of a large grapefruit. In Estonia, they can be seen almost everywhere in cultural landscapes, meadows, and bogs. They eat both animals and plants: plant seeds, soft plant parts, buds, flowers, and fruits. They are excellent climbers, which means that they can escape from most potential enemies, but being as small as they are still means that they have a lot of enemies, regardless of the numerous hiding places.