10 Things You Didn't Know About Naked Mole-Rats

Don't dismiss the fascinating mole-rat just because it's weird-looking.

A naked mole rat crawls out of a cave.

Josh More / Flickr / CC BY-NC-ND 2.0

Naked mole-rats aren't moles or rats, and they actually aren't even naked, despite what their name suggests. They are burrowing, bucktoothed rodents that look like miniature, skinny walruses, native to East Africa, and they have become a major source of fascination for scientists. Sand puppies, as they're also called, live a special lifestyle that has forced them to adapt in various ways. These adaptations give humans insight into their own well-being, from pain relief to cancer research to aging. Naked mole-rats represent a treasure trove of medical possibilities. Here are a few facts about these captivating (if a little weird-looking) creatures.

1. Naked Mole-Rats Are Eusocial

Naked mole rats sleeping together in their home.

Robin L / Flickr / CC BY 2.0

Similar to termites, ants, and other insects, naked mole-rats exhibit eusociality—an "evolutionarily advanced level of colonial existence," as described by the naturalist E.O. Wilson. There's a queen and one to three males with whom she reproduces, and the rest are either "soldiers," who protect the nests from snakes and other naked mole-rats; foragers, which gather food; or tunnellers. There could be up to 300 in just one colony. Besides the queen, females aren't physically capable of reproducing. Naked mole-rats are the first mammals to exhibit this structure.

2. Their Nests Are Big, But You May Not Even Notice Them

A naked mole rat crawling out of a hole.

Men In Black / Flickr / CC BY-NC 2.0

Apart from a volcano-like hole that serves as both its entrance and exit, an underground mole-rat burrow is often barely visible. There could be several miles of complex tunnel systems containing chambers and highly organized caverns under your feet, and you may never even notice it's there.

3. They Do Have Hair, and It Serves a Special Purpose

A close up of a naked mole rat.

Josh More / Flickr / CC BY-NC-ND 2.0

According to the San Diego Zoo, sand puppies are not entirely hairless (as their name wrongly suggests). They have about 100 fine hairs all over their bodies that mostly act as whiskers, helping the mole-rats to sense what's around them as they're virtually blind. The hair between their toes serves an added purpose: It helps the mole-rat sweep soil as it burrows underground.

4. They Don't Get Closer to Death as They Age

A naked mole rat rests on a rocky surface.

Josh More / Flickr / CC BY-NC-ND 2.0

A 2018 study published in eLife found that, unlike other mammals, naked mole-rats' risk of mortality doesn't increase as they age. Humans, in comparison, take the opposite approach, doubling their risk of death every year after the age of 30. For this anomalous mammal, however, the risk of death at age 6 months — around the time they reach sexual maturity — is one in 10,000. That number doesn't increase as they get older and, in fact, it can even decrease. The naked mole-rat can live to be 30.

5. They've Been Known to Kidnap Other Mole Babies

Naked mole rat baby feeding from mother.

Neil Bromhall / Getty Images

The co-op lifestyle doesn't always bode well for mole-rat offspring. An experienced queen can birth more than 30 pups in a litter, then convince her workers to care for them by feeding them her hormone-laced feces. In past studies, worker mole-rats have stolen the pups from the queen and put them to work in another, neighboring colony. Their tendency to care for young that aren't their own is an example of alloparenting.

6. Certain Proteins Help Them Stay Healthy

A naked mole rat eating a vegetable.

Josh More / Flickr / CC BY-NC-ND 2.0

In a regular digestive process, proteins are damaged and then recycled to form new proteins. Those that aren't discarded can become harmful to other cells, leading to various aging-related conditions. Naked mole-rats, however, are much more efficient at recycling their proteins. Their bodies tag fewer proteins for recycling because fewer proteins actually need it, according to a 2009 study published in Proceedings of the National Academy of Sciences of the United States of America (PNAS). This protein stability may be a clue to their longevity.

7. Naked Mole-Rats May Be Cancer-Free Thanks to One Gene

A naked mole rat crawling out of a cave.

Josh More / Flickr / CC BY-NC-ND 2.0

Another 2009 study published in PNAS found that naked mole-rats have a gene, "p16," that prevents cells from reproducing when they get too bunched up. This fail-proof gene prevents them from getting cancer, which is caused by aggressive cell growth. Given their long lifespans (and the fact that longer lifespans can often mean more cell growth), this discovery could help humans combat cancer, too.

8. Their Acid Insensitivity Is Aiding Pharmaceutical Research

Mole rats sleeping in a cave setting.

damian entwistle / Flickr / CC BY-NC 2.0

Because they spend so much time in cramped tunnels—where an excess of exhaled carbon dioxide leads to a buildup of acid levels—naked mole-rats have had to adapt to dire conditions. Early researchers expected to find their neurons without acid receptors. Instead, they found that the sodium channel that would normally send pain signals to the brain becomes blocked when acid molecules bind with their pain sensory receptors. This has been a pivotal discovery in the advancement of human painkillers.

9. They Can Go Long Periods Without Oxygen

Low-oxygen environments are deadly for most organisms, but these critters can live without air for 18 minutes, or with little air for up to five hours. They basically turn into plants. When there's limited oxygen, their system pumps fructose into their bloodstreams, then into their brains. Without this ability, surviving in burrows where oxygen is at a premium would be next to impossible.

10. Their Big Teeth Are Vital to Their Survival

A mole rat being held by a human hand.

John Brighenti / Flickr / CC BY 2.0

Naked mole-rats feast on tubers and roots, which requires strong chompers. According to the San Diego Zoo, those two prominent front teeth continue to grow but are kept at a reasonable length thanks to constant filing. They're also handy for tunneling, and their mouths remain soil-free because their lips seal behind their teeth. But the most exceptional feat? They can move each tooth individually, like chopsticks, to grasp things.

View Article Sources
  1. Braude, S. et al. "Inter‐Colony Invasion Between Wild Naked Mole‐Rat Colonies." Journal Of Zoology, vol. 313, no. 1, 2020, pp. 37-42. doi:10.1111/jzo.12834

  2. "Naked Mole-Rat." Smithsonian's National Zoo and Conservation Biology Institute.

  3. "Naked Mole-Rat." San Diego Zoo Wildlife Alliance.

  4. Ruby, J. Graham et al. "Naked Mole-Rat Mortality Rates Defy Gompertzian Laws by Not Increasing With Age." Elife, vol. 7, 2018, p. e31157. doi:10.7554/elife.31157

  5. Perez, V. I. et al. "Protein Stability and Resistance to Oxidative Stress Are Determinants of Longevity in the Longest-Living Rodent, the Naked Mole-Rat." Proceedings Of The National Academy Of Sciences, vol. 106, no. 9, 2009, pp. 3059-3064. doi:10.1073/pnas.0809620106

  6. Seluanov, A., et al. "Hypersensitivity to Contact Inhibition Provides a Clue to Cancer Resistance of Naked Mole-Rat." Proceedings Of The National Academy Of Sciences, vol. 106, no. 46, 2009, pp. 19352-19352-57. doi:10.1073/pnas.0905252106

  7. Smith, E. S. J. et al. "The Molecular Basis of Acid Insensitivity in the African Naked Mole-Rat." Science, vol. 334, no. 6062, 2011, pp. 1557-1560. doi:10.1126/science.1213760