Twenty-two species are recognized. Their size varies from 10 to 20 cm, with a tail of equal or slightly greater length; weight can be anywhere between 35 and 180 grams. The most distinctive feature of the kangaroo rats is their very long hind legs.
Kangaroo rats are found in arid and semi-arid areas of Canada, the United States and Mexico that retain some grass or other vegetation. Their diet includes seeds, leaves, stems, buds, some fruit, and insects. Most kangaroo rat species use their burrows and buried caches nearby to store food against the possibility of bad seasons.
Unlike the jerboas and hopping mice, but like their close relatives the pocket mice, kangaroo rats have large cheek pouches that open on either side of the mouth and extend back to the shoulders. They fill the pouches with food or nesting material ready for transport back to the burrow, then empty them by turning them inside out, like pockets, with their forepaws. There is a special muscle that, once the pouch is empty and clean, pulls it back in again.
The overall color of the kangaroo rats can be anywhere between pale, sandy yellow, and dark brown, with a white underside and often with white banding across the thighs. Tails tend to be dark with white sides and a tuft of longer hairs. Facial markings vary from one species to another, but all have an oil gland between the shoulders.