There are about 250 species of Sciurids currently recognized around the world. Eleven of these species can be found in North Dakota. There are three basic groups of squirrels. These are the flying squirrels which are active mostly at night, the tree squirrels which are active during daylight hours, and the ground squirrels. Because flying and tree squirrels are dependent upon mature trees, their distribution is limited to rivers, streams, woody draws, and urban areas where trees are plentiful.
Ground squirrels are more widespread and often abundant in grassland habitats.