The Underground Superheroes: 15 Fascinating Facts About Naked Mole-Rats

1. They live like ants, with a queen in charge.

Naked mole-rats are one of only two known eusocial mammals, meaning they live in colonies organised like those of ants, bees and termites. In each colony, a single female, the queen, and one to three males do all the breeding. Everyone else works as a non-breeding labourer, digging tunnels, gathering food, caring for pups or defending the colony.

2. They can live for more than 37 years.

Most rodents of their size live for only a few years, but naked mole-rats can live for more than 37 years in captivity. That makes them the longest-lived rodents known. A house mouse of similar size, by comparison, rarely lives beyond three years.

3. They hardly seem to age at all.

In most mammals, the risk of dying increases sharply with age. Naked mole-rats break this rule. Studies of large captive colonies have found that their risk of death stays roughly the same throughout their adult lives. Queens even appear to age more slowly than the workers they rule.

4. They almost never get cancer.

Naked mole-rats are remarkably resistant to cancer, which is very rare in the species. Scientists have identified several possible reasons, including an unusually thick form of a substance called hyaluronan that may stop cells from crowding together and forming tumours. Researchers hope that understanding these defences could one day help to fight cancer in humans.

5. They can survive for minutes without oxygen.

Underground burrows packed with animals can run very low on oxygen. A 2017 study found that naked mole-rats can survive for around 18 minutes with no oxygen at all. During this time, their heart rate drops dramatically and their bodies switch to burning fructose instead of glucose, a trick normally associated with plants.

6. They are almost cold-blooded.

Unlike nearly every other mammal, naked mole-rats do not keep their body temperature stable. Their temperature rises and falls with their surroundings, much like a reptile's. To stay warm, they huddle together in large groups or move to warmer parts of their burrow.

7. Their skin does not feel certain kinds of pain.

Naked mole-rats are insensitive to some types of pain that affect other mammals. Their skin does not react to acid or to capsaicin, the substance that makes chilli peppers hot. Scientists think this may be an adaptation to living in crowded burrows where high levels of carbon dioxide can make tissues acidic.

8. Their lips close behind their teeth.

Naked mole-rats dig with their large front teeth, which stick out of their mouths. Their lips seal behind the teeth, so they can gnaw through soil without getting a mouthful of dirt. About a quarter of all their muscle mass is used to close their powerful jaws.

9. They can run backwards as fast as forwards.

Living in narrow tunnels has made naked mole-rats experts at reversing. They can move backwards just as quickly as they move forwards. Sensitive hairs on their bodies and tails help them feel their way through the dark, since their tiny eyes are of little use underground.

10. Their colonies can number in the hundreds.

A typical colony contains around 75 to 80 animals, but some have been found with nearly 300 members. They live in vast underground tunnel systems that can stretch for several kilometres in the dry regions of East Africa, including Kenya, Ethiopia and Somalia.

11. Each colony has its own accent.

Naked mole-rats communicate with a range of chirps and squeaks. A 2021 study found that each colony has its own distinctive "dialect" of soft chirps, which helps members recognise one another and spot intruders. The dialect appears to be set by the queen, and pups adopted into a new colony learn the local version.

12. Big workers act as soldiers.

Within the workforce, larger mole-rats tend to dig tunnels and act as soldiers, defending the colony against snakes and rival mole-rats. Smaller workers handle jobs such as foraging, building nests and caring for pups. When a new food source is found, the discoverer calls others to help.

13. They eat underground tubers without killing the plant.

Naked mole-rats feed mainly on large tubers and roots. Instead of eating an entire tuber, they often eat only the inside and leave the outer part intact, allowing the plant to regrow. This means a single tuber can feed a colony for months or even years.

14. The queen grows longer when she takes power.

When a female becomes queen, she does more than start breeding. Her spine actually lengthens, giving her a longer body to carry large litters of pups. Queens can give birth to litters of up to around 20 pups or more at a time.

15. They are not actually completely naked.

Despite their name, naked mole-rats are not entirely hairless. They have around 100 fine hairs scattered over their bodies, which work like whiskers to help them sense their surroundings. Their pink, wrinkly skin lacks the insulating fat layer found in most mammals.