Naked mole rats are small, almost hairless rodents, about 10cm long, that live in eastern and southern Africa. The structure of a mole rat colony is identical to that of hive insects such as bees. There is one female, a queen, who mates with a handful of fertile males; the rest of the colony consists of sterile "workers".
They can run backwards as fast as forwards, can manipulate their incisor teeth individually like chopsticks and unlike all other mammals, naked mole rats are not truly warm-blooded.
The oddities continue. Mole rats appear unable to feel pain, at least on their skin. The pain receptors found in all mammals - called nociceptors - are there, but they appear to be turned off. (It is finding out how these nociceptors operate that could be the key to new treatments for arthritis.)
In terms of cancer, numerous studies have failed to find a single tumour in the thousands of individuals sampled.
Finally, these little rodents live for around 30 years - 10 to 20 times the lifespan of relatives such as rats and mice.
It is, however, that resistance to cancer that has proved the most intriguing puzzle. Now, Vera Gorbunova and colleagues at the University of Rochester in New York have identified a polysaccharide found in naked mole rat cells that stops tumours growing.
The scientists, whose study was published in the current edition of Nature, suggest that the finding "opens new avenues for cancer prevention and life-extension".
The chemical, called high-molecular-mass hyaluronan (HMM-HA), acts as a kind of lubricant, allowing mole rats to squeeze their bodies through the smallest tunnels.
It seems, therefore, that the ability of HMM-HA to confer cancer resistance was a happy evolutionary accident. And one day, it may be possible to engineer the ability to produce HMM-MA in human tissues.
