Naked mole rats are fairly small, typically around 9 cm long and weigh between 30 and 35 grams and are found in Eastern Africa, in Ethiopia, Kenya, and Somalia in groups of up to 80 individuals. Well-adapted to living underground in tunnels, they have an elongated body, short legs and small eyes. Sir David Attenborough describes the naked mole rat in beautiful detail in David Attenborough's Natural Curiosities.
Unusually for a mammal, naked mole rats exhibit eusociality, similar to that seen in some ants, termites, bees and wasps. The colony has one breeding female (the queen), a small number of males with the rest being sterile workers.
The queen produces a hormone and is extremely hostile which suppresses the workers from becoming queens. However, if the queen dies along with the hormone suppressant, a violent struggle ensues between potential new queens until one is establishes.
Living underground and rarely coming up to the surface means that naked mole rats have to find their food underground. They dig their tunnels, using enlarged teeth and jaw muscles, in search of underground tubers. Their lips also close behind their teeth to stop dirt getting in their mouths!
The naked mole rat perfectly fits Alexander's description of what a eusocial mammal should be like.
The Long Life
Living up to almost 30 years old, naked mole rats live an extraordinarily long life for a rodent of similar size. They are incredibly resistant to cancer with some of the long-life attribution been put down to their stop-start lifestyle. They are able to tolerate harsh periods by lowering their metabolism and this, it is suggested, may be one of the clues to their long life.
- They are also known as sand puppies or desert mole rats.
- The Damaraland mole rat is the only other known eusocial mammal.
- Naked mole rats cannot feel pain in its skin.
- Up to 25% of their musculature is used in closing their jaws.
- Bacteria in their intestines help to digest their staple diet; tubers.