The Fat sand rat (Psammomys obesus) is one of the most curious little rodents of the desert, found in North Africa and parts of the Middle East. Despite its name, it’s not really a “rat” at all, but a chunky, round-bodied gerbil that looks more like a hamster dressed in sandy camouflage. It has a stubby tail, short ears, and a thickset body, giving it a plump appearance that inspired its name. Covered in soft, brownish-gray fur that blends perfectly into desert scrublands, the fat sand rat is a specialist in thriving where few other animals can—arid, salty, and plant-poor environments.

What makes the fat sand rat truly special is its extreme dietary specialization. While most rodents are flexible eaters, happily chewing on seeds, fruits, and insects, the fat sand rat lives almost entirely on salty desert plants, especially saltbush’s tough, bitter leaves (Atriplex). These plants are low in calories and high in salt, which would make them nearly inedible for most animals. To survive, the fat sand rat has developed an incredibly efficient digestive system that squeezes every last bit of energy out of these harsh meals. Its kidneys are also adapted to conserve water, allowing it to live without drinking, getting all the moisture it needs from its salty food. Compared to other gerbils that eat energy-rich seeds, this species is unique in surviving on such poor-quality, salty vegetation.

But here’s where things get even more fascinating: in captivity, when fed a “normal” rodent diet rich in grains, fruits, and vegetables, fat sand rats tend to develop obesity and type 2 diabetes. This makes them an important animal in medical research, helping scientists understand human metabolic diseases. In the wild, their tough diet keeps them lean and healthy, but their bodies aren’t built to handle rich foods in captivity.

Distribution

Country

Population est.

Status

Year

Comments

Algeria

2016

Egypt

2016

Israel

2016

Jordan

2016

Libya

2016

Mauritania

2016

Morocco

2016

Saudi Arabia

2016

Sudan

2016

Syria

2016

Tunisia

2016