The San Diego Pocket Mouse occurs in desert and coastal habitats in southern California, Mexico, and northern Baja California, from sea level to at least 1,400 m. Yellowish or orange hair on its sides contrasts with a dark brown back, and its ears are relatively small. Learn more about the Chaetodipus fallax, more commonly known as a San Diego Pocket Mouse, in this easy-to-read species overview by the Smithsonian's National Museum of Natural History.