The Naked Truth

The Naked Truth

Everything You Didn't Know About Naked Mole-Rats

BY JARED MOELLER, ANIMAL CARE CURATOR

If I asked you, what is the most interesting animal to call The Living Desert’s Rhino Savanna habitat home, what would you answer? The black rhinoceros with its giant frame and prehistoric look? Would it be the small but wiry dwarf mongoose? What if I said it is the naked mole-rat?

The first thing that makes naked mole-rats interesting is that their entire name is somewhat a lie. First, they are not completely naked, they have whiskers and 100 tiny hairs spread around their body allowing these effectively blind animals to feel their way through their pitch-black homes. Second, they are not related to moles at all. Finally, though they are rodents, they are not rats, in fact they are more closely related to porcupines and guinea pigs.

Mole-rats are one of the few mammals that do not regulate their body temperature.

PHYSIOLOGICAL MARVELS

There are so many fascinating elements about naked mole-rats, it is tough to know where to begin, but perhaps it is best to start with their unique physiological traits. Mole-rats have an extreme tolerance to pain. Certain pain receptors have genetically been “turned off,” effectively meaning they do not feel certain types of pain—they do not feel the effects of acids or even chili peppers. Even lactic acid build-up in their muscles does not affect them like it does us, allowing them to live comfortably in their low oxygen, high carbon dioxide tunnels miles below the surface.

Mole-rats are incredibly long-lived animals, living into their 30s—which is about the same as black rhinoceros! This is a remarkable trait as smaller animals tend to live shorter lives overall. Living this long is even more impressive because mole-rats are one of the few mammals that do not regulate their body temperature— hence why you can find them sleeping in a big pile. They heal remarkably fast; we often find minor injuries heal in just one day. Due to these traits naked mole-rats are a highly studied species, in particular for cancer research. Mole-rats seem to be almost completely resistant to cancer as they rarely, if ever, develop the disease.

Incredibly, every naked mole-rat you see in one of our two colonies is essentially a clone. Though they are not clones in the traditional sense, like Dolly the sheep, colony members are so inbred that, genetically speaking, they are basically clones. For most species, this level of inbreeding would become highly detrimental, but for some reason, naked mole-rats seem resistant to the ill effects and exist this way naturally.

SOCIAL STRUCTURE

Naked mole-rats almost have more in common with insects than they do other mammals. They are eusocial animals, which means their social lives are similar to termites and bees. Mole-rat colonies revolve around one singular female, known as the queen. This queen does all the breeding for the entire colony and can usually be identified as she is significantly larger than all the other rats, owing to the fact queens grow longer each time they have a litter of pups. Each colony has 2-4 drones who are the males that breed with the queen. The rest of the colony is made up of workers who are responsible for pup care, expanding the tunnels, and foraging for food. Colonies of naked mole-rats also have a caste of soldiers who are tasked with defending the colony; soldiers are slightly larger than workers with thicker necks and jaws. Lastly, there is a rare type of naked mole-rat born into colonies called a dispersiform, who does not take part in daily activities of the colony and will eventually be a rare immigrant to a new colony.

INSIDE LOOK! The naked mole-rat habitat is connected by a series of tunnels.

THE GAME OF THRONES

Queen mole-rats are not benevolent rulers; the only way a new queen is crowned is through fighting. If a queen dies the most dominant females will soon fight for the “crown,” the winner often killing the other challengers. However, even a healthy queen is not completely safe from usurpers as any female may challenge the queen for power at any time. Challengers may even have loyal subjects who will help them spark a civil war to take over. A former queen’s allies may even cause trouble after a new queen takes over.

Basically, "Game of Thrones" might as well have been about naked mole-rats! All this political intrigue makes minor conflicts among colony members quite common, and the Rhino Savanna team monitors these conflicts closely. But as mentioned previously, even though their fights can look really bad, they are the toughest animals on Rhino Savanna. On your next visit, consider taking a closer look at these magnificently unique creatures.