The fulvous Harvest Mouse is a nocturnal species that lives in grassy fields where there are shrubs. These Mice are good climbers, and build baseball-sized nests up off the ground, in vegetation. Learn more about the Reithrodontomys fulvescens, more commonly known as a Fulvous Harvest Mouse, in this easy-to-read species overview by the Smithsonian's National Museum of Natural History.