I had never heard of the naked mole rat – that was until today when I received one of those emails that makes its way round the office, providing a little light entertainment en route.
For everyone else who has never heard of the naked mole rat either, I thought I would enlighten you with a few fascinating animal facts on this little burrowing creature…
The naked mole rat (Heterocephalus glaber) is indigenous to East Africa; a rodent which lives in underground colonies in the arid soils of Somalia, Ethopia and Kenya.
Busy Little Burrowers
Clusters of 100 or so of these wrinkly creatures are typical and their tunnel system can spread two or three miles along and down. The network connecting their bedrooms, larders and lavatories is made by an assembly line of little naked workers who gradually pass the dirt back from the front digger, who makes good use of his giant buck teeth, and eventually up and out above the ground to form characteristic mole hills.
The naked mole rats’ social behaviour and reproductive patterns are less rodent- or mole-like however, and rather more comparable to that of bees or ants. Each colony has one mole rat who’s in charge; a female naked mole rat; the ‘queen bee’; whose sole job in life is to produce off-spring. All the other subordinate mole rats are then caste as burrowers, soldiers or man-servants to the queen mole-rat.
When Push Comes to Shove
The queen mole rat ensures she is the only female to reproduce by surpressing the fertility levels of other female mole rats in the colony – she bully’s them into submission by ‘shoving’ them around. The effect of all this shoving is that the other females stop ovulating or never even start.
Now for the queen, being the only reproducing female, you’d think there’d be a lot of male attention… her solution is simple though – just shove the males into submission too and that way they won’t be distracted from their jobs either. The effect on these males is that their testosterone levels are greatly reduced.
So there remains only a handful of breeding males, but even these aren’t as lucky as you may initially think – she can regulate their testosterone levels too. It’s the queen who chooses when she’s ready to mate and these lucky little males can do little to deny their sexual urges once she allows their testosterone levels to reboot. They don’t even realise they have no control over the matter!
Feel No Pain
Well if you think that the queen mole-rat is a cold, heartless creature who feels no sympathy or remorse for the effect she has on those around her; it may comfort you to know that mole rats don’t feel pain. Maybe not all pain, but certainly some types.
Mole rats lack a chemical, specifically, a neurotransmitter which would normally send pain signals to the nervous system. The rat therefore feel no immediate pain to cuts, scratches or heat.
Interestingly, medical researchers believe that an excess of this same neurotransmitter in humans is the cause of some chronic pain in tissues and ligaments. If the concentration of the neurotransmitter can be reduced, the chronic pain could be eliminated – and the naked mole rat may hold the answer.
It’s not known however, why the mole rat does not have this chemical, which is common in all other mammals. One thought is that they evolved without the neurotransmitter as a mechanism to cope with high levels of carbon dioxide present in their underground tunnels, which would normally be expected to cause the type of pain associated with this chemical.
Secret of Eternal Youth
Naked mole rats are, for their size, a very long-living mammal. Indeed, a 28-year old mole rat still has the body of a three-year old. How, you might ask, do they manage this?
Well, it may have something to do with their ability to lower their metabolic rate so dramatically as to effectively shut it down.
Another idea is that generally animals put their resources towards growing and maintaining tissues or towards reproduction. Since the majority of naked mole rats are, involuntarily, sexually disinclined they can expend all their resources on their own body and hence will naturally live longer.
A 28-year old mole rat may have the bones, heart and lungs of a youngster and so potentially hold the secret to a long, healthy life. The mole rat on the other hand, was born wrinkly as a dried prune, and so it will never reveal the secret to eternal youthful beauty. Too bad.
The naked mole rat is perhaps the ultimate subject for anti-wrinkle cream manufacturers though.
Cold, Naked and Blind – as the day they were born
Naked mole rats are great team-workers and one way they work together is to overcome their inability to regulate their own body temperature. So when they’re cold they huddle together to increase their overall body mass. When they’re hot, they disperse deeper into the cool ground.
Naked mole-rats are almost blind; probably not that surprising as it’s dark underground so they wouldn’t see much even if they had 20-20 vision. A good thing really – I can’t imagine any ‘love at first sight’ between these, quite frankly, butt-ugly (and naked) little burrowers.
So there you have it…
The Naked Mole Rat Truth
For the end of this article, I leave you with the image which first brought to my attention the existence of this fascinating little animal:
If you’re having a bad day and feeling sorry for yourself, remember…
…you could look like a penis with buck teeth.
- National Geographic – Mole rat profile
- Science Daily – Naked mole rats bear pain relief clues
- Science Daily – Stressed-out naked mole rats may provide clues about human infertility
- Bio-Medicine – Strange Sex Life of Mole-rats may Provide Clues About Human Infertility
- USA Today – Naked mole-rat’s longevity secret cloaked in mystery
- Gray Lyons – Animal Behaviour, Naked mole rat
- Heterocephalus glaber – by Debbie Ciszek
- Live Science – Strange Creature Immune to Pain
Source of image unknown so author credit not available