The appearance is very similar to the
northern hopping mouse: slightly larger than a common
house mouse at head-body length and an average weight of . As with all
hopping mice, the hind legs are greatly elongated, the fore limbs small, and the brush-tipped tail very long—about . The fur is chestnut or fawn above, pale below, with a grey wash about the muzzle and between the eye and ear, and longer, coarse black guard hairs on the back. The tail is sparsely furred and pink, darker above than below. Spinifex hopping mice live in small family groups of up to 10 individuals in deep, humid burrow systems. Typically, there is a large nest chamber lined with small sticks and other plant material about a metre below the surface, from which several vertical shafts lead upwards. Shaft entrances do not have spoil heaps. ==Breeding==