The naked mole rat (Heterocephalus glaber) also known as the sand puppy or desert mole rat, is a burrowing rodent native to parts of East Africa and is the only species currently classified in the genus Heterocephalus. The naked mole rat and the Damaraland mole rat are the only known eusocial mammals. It has a highly unusual set of physical traits that enable it to thrive in an otherwise harsh underground environment; it is the only mammalian thermoconformer, has a lack of pain sensation in its skin, and has very low metabolic and respiratory rates.The naked mole rat is well adapted for the limited availability of oxygen within the tunnels that are its habitat: its lungs are very small and its blood has a very strong affinity for oxygen, increasing the efficiency of oxygen uptake. It has a very low respiration and metabolic rate for an animal of its size, about 2/3 that of a similarly sized mouse, thus using oxygen minimally. In long periods of hunger, such as a drought, its metabolic rate can be reduced by up to 25 percent.The naked mole rat is native to the drier parts of the tropical grasslands of East Africa, predominantly southern Ethiopia, Kenya, and Somalia.
Clusters averaging 75 to 80 individuals live together in complex systems of burrows in arid African deserts. The tunnel systems built by naked mole rats can stretch up to three to five kilometres (2–3 mi) in cumulative length.