The fat sand rat lives in colonies in complex burrow systems, which have separate areas for nesting and the storage of food (3). Compared to other members of the Muridae family (the mice, rats and gerbils), the fat sand rat is rather unusual as it is diurnal and wholly herbivorous; most other species in this family are nocturnal and feed primarily on grains (granivorous) (4). Its diet consists of leaves and stems and, unlike high-energy seeds, these foods are rather low in energy. As a result, it has to eat around 80 percent of its body weight in food each day to obtain sufficient energy (5). The fat sand rat does not need to drink water, a useful adaptation in arid habitats, and instead can get all the water it needs by feeding on the leaves of the saltbush (Atriplex halimus), which are up to 90 percent water (4). However, this water has an extremely high concentration of salt, and so the fat sand rat must produce very salty, concentrated urine in order to expel the salt from its body (4) (5).
Breeding may take place all year round, although a peak of breeding activity has been reported between September and May (6). The female gives birth to a litter containing two to ten pups after a gestation period of 23 to 25 days (7). This species reportedly has a lifespan of around three years (7)