chipmunk, (genus Tamias), any of 25 species of small, striped, terrestrial squirrels with large internal cheek pouches used for transporting food. They have prominent eyes and ears, a furry tail, and delicate claws. All are active only during the day, and all but one are North American, occurring from southern Canada to west-central Mexico. Body length among most species ranges from 8 to 16 cm (3.1 to 6.3 inches) and tail length from 6 to 14 cm (2.4 to 5.5 inches). Chipmunks are basically pygmy squirrels adapted to exploiting the resources of rocky terrain and forest understories. They scamper along ...(100 of 542 words)