Mole-Rats

Mole-rats are small, fossorial rodents, which means they spend their entire lives underground in a sealed burrow system. Native to Africa, these little animals are found from the southernmost tip of the continent to about 10 degrees north of the equator. Mole-rats make up the family Bathyergidae, which includes 12 species in five genera (not to be confused with an unrelated family Spalacidae, containing a single genus living in eastern Europe and the eastern Mediterranean region). As a group, bathyergid mole-rats have the greatest diversity of both body size and social structure of any subterranean rodent. The species in three genera (Bathyergus, Georychus, and Heliophobus) are completely solitary. The species in the other two genera (Cryptomys and Heterocephalus) are social. The most social of all is also the smallest: weighing in at around 0.8 oz (23 g), the naked mole-rat (Heterocephalus glaber). It lives in highly cooperative groups, sharing food, living quarters, and care of the young. At the other end of the spectrum is the solitary Cape dune mole-rat, in which adult males may weigh up to 63 oz (1.8 kg).