Thursday 22 July 2010

Naked Mole Rat

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First thing's first, the naked mole rat is one ugly animal. So ugly in fact, it almost pulls off a full 180 to become quite cute! The rather unnerving appearance is perhaps understandable given its unforgiving lifestyle and habitat; the mole rat lives underground in the hotter, drier more uncomfortable parts of east African grassland. Almost totally hairless, almost totally blind and, being a rodent, in possession of huge, constantly growing teeth, the naked mole rat is perfectly adapted to a life of dark tunnels and tunneling in darkness. They can even walk backwards as quickly and confidently as they walk forwards. Their blood has a stronger than usual affinity to oxygen and it has a lower metabolic and respiratory rate than other small rodents, meaning that the mole rat needs less food and less oxygen than you'd expect. They are also unable to feel pain in their skin, this is believed to help them survive as all that carbon dioxide would cause a build up of acids in their body. You can't have the little blighters itching and getting cramp the whole time, can you?

When I first saw the naked mole rat, I thought it had no lips. In fact, its lips are behind the teeth so it can chew through the earth without eating it, which is pretty useful when all that tunneling is in aid of discovering food, not for fun and larks. Food for these creatures are underground tubers dotted around their landscape, fat chunks of nutrition that plants build up to let them grow when the climate is more clement. Apparently, they discover these morsels by sheer chance, just bumping into them as they dig. Lucky then, that by eating only parts of a tuber and allowing it regenerate, a single tuber can feed a whole colony of naked mole rats for months or even years.

Wait... did I say colony? Yes! These mole rats don't live alone, they are what is called "eusocial". They have a queen, one to three breeding males and everyone else is a sterile worker, some gathering food, others defending the nest. This is the norm amongst ants and termites but extremely rare in mammals. In fact, the only other known example is from another kind of mole rat! One who has a load of fur as it happens. Colonies can have as many as 300 members, although 75 is the average and in the confines of the narrow tunnels, rank is key; when two naked mole rats bump into each other, the senior passes by on top and the junior gets on his belly and lets her do it. (You can change the his/her to whatever you prefer, I don't mind.) Add to this the facts that the naked mole rat has been seen to live to the astonishing age of 28 (it's the longest living rodent of them all, actual rats live until about 3) and that it has an unusually high resistance to cancer, and you end up with a very interesting little monster.

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