The Naked Mole-rat (Heterocephalus glaber) is a nearly hairless and nearly sightless East African subterranean rodent that lives in colonies consisting of dozens of individuals (sometimes more than 200). These colonies have a complex social structure. In Naked Mole-rat colonies, multiple adult generations are present and at any time just a single female (the "queen") and one to three males are reproductive; the other individuals work together to provide cooperative brood care for the colony's young. Animal species with these traits are often referred to as eusocial (although eusociality is sometimes defined more strictly to include only species in which individuals have irreversible roles, which is not the case for Naked Mole-rats).
Naked Mole-rats are often kept in zoos and are very popular with both the general public (charmed by their unusual appearance and habits) and with researchers studying a range of topics from the evolution of social behavior to longevity. Naked Mole-rats have unusually long potential life spans, exceeding 30 years. Based on long-term observations of large captive colonies, these rodents appear to be remarkably resistant to cancers, an observation that has piqued the interest of researchers. A 2013 report in the journal Nature (Tian et al. 2013) identified an apparent molecular mechanism to account for the lack of detected tumors and the authors speculated that these particular molecular features of the Naked Mole-rat's tissues may have evolved initially to increase skin elasticity, facilitating living and moving in tunnels, but provided the side benefit of decreasing or eliminating tumor development, which might then have been favored by natural selection (a popular account of this work was published in The New York Times (June 19 2013 by Carl Zimmer).
