Why do humans live so long? The African naked mole rat might have the answer. Something is keeping us alive, and we do not know what it is. Now, a real Methuselah of the mammals is beginning to hint at what it takes to make a century. The African naked mole rat, whose name describes its charming appearance, has a pair of fearsome front teeth.
It lives in burrows in which one aggressive female prevents all the others from mating and forces them to look after her own offspring. The animal is about the same size as a mouse, but it lives eight times as long, with plenty getting to 30 or so.