A rodent which lives in colonies underground, digging with its enlarged front teeth. Only one female in a colony breed, and her offspring become workers or soldiers, helping dig the burrows in search of tubers underground.

Life span
Unknown. In captivity some mole-rats have lived to 25 years old.

Statistics
9-12cm long.

Physical description
Small rodents with cylindrical bodies and short limbs, adapted for burrow-living. The eyes are tiny and can only detect light and dark. The incisors are large and protrude out of the mouth, with the lips closing behind them. These are used for digging. The external ears are also tiny, and the skin almost hairless, pink and saggy. There are whiskers and sensitive guard hairs scattered over the otherwise naked body.

Distribution
East Africa.

Habitat
Burrow systems in arid areas.

Diet
Roots and vegetation.

Behaviour
Naked mole-rats (like Damaraland mole-rats) live in social colonies of about 80 individuals (occasionally up to 300) underground, digging tunnels to find roots and tubers. After rain the ground is soft enough to dig (using the incisors), but rain is rare and may only fall every few months. The colony 'farms' tubers by eating part of them and then blocking the tunnel to let them regenerate, helping guarantee a constant food supply. In each colony a single female and 1-3 males breed, whilst the rest remain as workers, helping provision the colony. Only the breeding female suckles the young. Whilst most offspring become workers, some continue to grow and become colony defenders, and should a breeder die, a defender will become reproductive to replace them. They can occasionally disperse to found a new colony with an unrelated member of the opposite sex.

Reproduction
The breeding female somehow suppresses the breeding of all the other females in the colony, although they can regain their fertility quickly if the breeding female is removed (and will fight to the death sometimes to become the breeding female of the colony). The worker males are also suppressed, although they do produce some sperm. Gestation is 66-74 days after which a litter of 2-5 pups are born.

Conservation status
Not threatened.

Notes
The naked and Damaraland mole-rats are the only known eusocial mammals, behaving like social insects by living in a colony with a single breeding female and related, reproductively suppressed, workers and soldiers.