Fat sand rat

(Psammomys obesus)




Facts about this animal

The fat sand rat is a large, stocky gerbil species with a head-body length of 13-19 cm and a tail of 11-15 cm. It has short and rounded ears. The tail is fully haired and has a black terminal tuft. Differently from Meriones, the incisors of the fat sand rat have no groves. Its upper parts are reddish-brown, reddish, yellowish or sandy buff. The underparts are yellowish, buffy or whitish.


Fat sand rats live in sandy saline deserts with sparse vegetation. They are active both in the day and night. In winter, main activity is during the day, but during the summer months they prefer the shade and can be found inside the burrow or in the shade of the surrounding bushes. They build complex burrow systems which have separate chambers for nesting, breeding and storage of food.


The fat sand rat feeds predominantly on the salt bush plant (Atriplex halimus) supplemented by some leguminous plants, annuals and occasional insects. It copes with the high salt intake in its diet by having extremely efficient kidneys that produce urine with a high salt intake without being toxic to the animal. Sand rats rarely drink water, having their needs met by their diet and the licking of morning dew. They appear in the early morning hours at the mouth of the burrow cleaning out dirt and excreta, only after these home cleaning activities are done does it begin its foraging.


Fat sand rats are solitary living in individual burrows except for females with offspring during the breeding season which is January to April. Gestation lasts usually 25 days but may be extended up to 36 days after postpartum mating. Litter size is usually 2-5. Weaning occurs at about 3 weeks of age, and females conceive first when about 3 to 3 ½ months old.

Did you know?
That the fat sand rat got its common name from when diabetes was first discovered by chance observation in the specimens collected by the US Naval Medical Research Unit in Egypt? It appeared when animals were maintained on a regular rodent diet and gained too much weight. Psammomys obesus represents an excellent animal model of obesity and type 2 diabetes that exhibits a phenotypic pattern closely resembling that observed in human population studies.


Name (Scientific) Psammomys obesus
Name (English) Fat sand rat
Name (French) Rat des sables, Psammomys obèse
Name (German) Fette Sandratte
Name (Spanish) Rata del desierto
CITES Status Not listed
CMS Status Not listed



Photo Copyright by
Tino Strauss



Range Algeria, Libya, Egypt, Sudan, Palestine, Saudi Arabia, Tunisia, Syria, Jordan
Habitat Sandy saline deserts with sparse vegetation
Wild population Unknown, but stable (Red List IUCN 2011)
Zoo population 47 reported to ISIS (2006)

In the Zoo

Fat sand rat


How this animal should be transported

For air transport, Container Note 79 or 81 of the IATA Live Animals Regulations should be followed.


Find this animal on ZooLex


Photo Copyright by
Vladimír Motyčka

Why do zoos keep this animal

The fat sand rat is kept primarily for educational reasons as an animal adapted to salty desert conditions and proving the opportunity to tell stories about obesity and diabetes. Because they are active during the day, they are more suitable for public display than many other mouse or vole species.