All Washington ground squirrels live in burrows which they construct themselves. The life histories of the two striped species are less well known than those of the more economically important species. All species hibernate. The striped species disappear in October and reappear the following March. This can be called true hibernation. The long-tailed ground squirrels probably hibernate at high altitudes but aestivate in more arid localities. In Washington the Douglas ground squirrel occupies an area that is relatively temperate and humid. They may hibernate or aestivate, depending on local conditions, or they may remain active all year. The spotted ground squirrels disappear in midsummer and sleep (aestivate) until the following spring, for in their arid habitat the disappearance of green food in late summer and fall makes living conditions almost as unfavorable as in winter. Townsend ground squirrels range from central Washington south to southern Nevada and from the Cascade Mountains east to eastern Idaho and central Utah. Five races are recognized, only one of which occurs in Washington, where it is confined to the Upper Sonoran Life-zone. It occupies the sagebrush area, being most common where the sage is in scattered clumps separated by grassy areas. Occasionally these squirrels occupy extensive grasslands where sage is scarce and in the Yakima area may enter pastures and fields. They live in colonies, often with more than ten separate burrows to the acre. Burrows are dug in dusty ground, either near sage bushes or in openings among them. Well-worn trails lead from feeding places to openings of burrows. Mouths of burrows are usually situated on flat ground and are surrounded by a rim of excavated earth four to six inches high. If located on a slope, the excavated earth collects as a mound on the lower side, and serves as a look-out post for the squirrels. Burrows excavated by Scheffer are described by Howell (1938: 5). One reached a depth of 5-1/4 feet at a point where it branched 11 feet from the entrance. One branch led to the nest chamber three feet to the right of the main tunnel. The other reached a depth of six feet at a point 14 feet from the entrance, then turned upwards at a 70 degree angle and reached the surface through a partly obstructed entrance, 12 feet from the original entrance. The nest chamber was 6-1/2 inches in diameter and filled with a perfectly dry nest of fine grass, partly broken and shredded. Food consists of soft green vegetation and seeds. Foods listed by Howell (1938: 5) include: _Sphaeralida munroana_, _Plantago purshii_, _Bromus tectorum_, _Agropyron pauciflorum_, _Oryzopsis hymenoides_, _Norta altissima_, _Artemisiae spinescens_, sunflower, alfalfa, wheat, barley, potato, beets, carrots, lettuce, and insects (grasshoppers, cicadas). In 1917, these squirrels were reported to have practically destroyed a ten-acre field of beets at White Swan, Yakima County.