The silky pocket mice are small animals with soft fur, long tails, and small feet compared to other heteromyids. They have long claws which they use for digging burrows and sifting sandy substrates for seeds. They have also been found to steal seeds from kangaroo rats' dens. They store these seeds in large hairy external cheek pouches. They are nocturnal and are found in arid habitats. They are not true hibernators, but will go into torpor and stay in their burrows for extended periods of time.