Naked mole-rats are curious little creatures, neither moles nor rats. Although their hairless exteriors don’t make them the cutest rodents, they’re certainly fascinating. Let’s learn more about the unique naked mole-rat.
Naked Mole-Rat Physical Attributes
Naked mole-rats are, of course, hairless. They have pink, wrinkly skin and rat-like tails. Despite their name and appearance, these little critters are more closely related to species such as the porcupine, chinchilla, and guinea pig than they are to rats.
Naked mole-rats’ skin is translucent on their undersides and light purplish-brown on their backs and tails. They resemble moles a bit in size and shape, but with shorter and broader heads. They have powerful jaw muscles and large incisors. They live mostly underground in tunnels, so their overlarge incisors come in handy.
Naked mole-rats aren’t large, usually measuring about three inches long and weighing 1.5 ounces. Depending on their role in the colony, however, they can weigh more:
- Soldiers: up to two ounces
- Queen: up to 2.5 ounces
To cut through dense underground roots and hard, packed soil, naked mole-rats have powerful jaw muscles. One-quarter of an individual naked mole-rat’s muscle mass is localized in its jaw.
Naked Mole-Rat Habitat
Naked mole-rats are native to eastern Africa. They’re typically found in:
Naked mole-rats only live in underground burrows and tunnels and they prefer grassy, semi-arid regions. Naked mole-rats found outside of eastern Africa typically live in zoos or other conservation areas.
They like habitats with plants that have large underground roots and tubers. Naked mole-rats eat these roots, which requires pretty strong teeth. By feeding on these underground roots and tubers, they’re able to absorb enough moisture, so they don’t need to drink water. Because they’re always in the dark, naked mole-rats have terrible eyesight.
Naked mole-rat tunnels are about 1.5 inches in diameter and can be just below the surface or six feet deep. The colony’s branching network of tunnels can measure out to 2.5 miles in total. Naked mole-rats have different areas in the burrows, such as nesting chambers, toilet rooms, and food sources.
Naked Mole-Rat Eating Habits
The large, underground tubers that naked mole-rats eat can be one foot in diameter. When they consume such a large tuber, they’ll typically only bore through and eat the inside, leaving the outer layer intact. By doing so, the plant may remain healthy and keep growing, providing the mole-rats with a sustainable food source. In addition to tubers, they also eat roots, bulbs, and other plant storage organs found underground.
Because the underground plant parts that naked mole-rats eat are high in cellulose, they’re hard to digest. Like other herbivore rodents such as rabbits and guinea pigs, naked mole-rats ingest their feces to help them maximize the nutrients they get from their food.
Naked mole-rats typically gather food into a food chamber, where every member of the colony can share. As soon as a scout finds a food source, it will alert the other scouts and they will take the food back to the food chamber, piece by piece.
Naked Mole-Rat Colonies
Naked mole-rats live in colonies, like ants. Each member of the colony has a specific job to do, and the colony is led by a queen. The queen is the only female naked mole-rat who reproduces in the colony, and only a select group of males may mate with her. Most of the naked mole-rats in a colony serve as soldiers or workers. The soldiers protect the colony from external threats, whereas the workers may have any number of tasks:
- Scouting for food
- Digging tunnels
- Caring for the queen’s young
Because the queen is the only female mole-rat in the colony to bear pups, she’s larger than the rest of her colony. Queens aren’t born or chosen at random; female naked mole-rats in the colony will fight each other (sometimes to the death) to be queen. Once the colony has a queen, that queen must continually fight off attempts from other female members of the colony to take over her position.
Although naked mole-rats are mammals, their lack of internal temperature regulation essentially makes them cold-blooded. To prevent heat loss, naked mole-rats huddle together in large masses. They may also dig shallow surface tunnels so they can warm themselves in sunlight.
Naked Mole-Rat Reproduction and Development
In naked mole-rat colonies, only the queen gives birth to pups, and it’s her only job. The workers bring food to her all day so she can focus solely on reproduction and pup-rearing.
Queens can give birth to a new litter of pups about five times per year. The number of pups per litter varies substantially, sometimes with 12 pups and other times reaching as many as 30. The queen nurses the pups for about four weeks, but the pups can start eating solid food at two weeks old. Just like adult naked mole-rats, pups need pre-digested feces to help them absorb nutrients. Adult workers provide the needed feces for the queen’s pups.
After about one month, the pups may begin digging, sweeping, and carrying, and soon start helping out the colony.
Naked Mole-Rat Lifespan
Naked mole-rats have an unprecedented lifespan for small rodents, living between 10-30 years. The maximum longevity of these animals is still unknown, but the longest a naked mole-rat has lived in human captivity is 30 years.
Naked mole-rats reach sexual maturity by age one but only the queen and a select number of male naked mole-rats reproduce. An individual mole-rat may go its entire life without ever having reproduced, even though it maintains the capability to do so.
Naked Mole-Rat Conservation
Naked mole-rats are not at risk when it comes to conservation. According to the Smithsonian’s National Zoo & Conservation Biology Institute, their conservation status is currently Least Concern, the least threatened status for animal species.
In the wild, naked mole-rats live in areas with little human development, so their habitats aren’t disturbed. In Kenya’s national park system, naked mole-rats are a protected species.
Do Naked Mole-Rats Have Their Own Language?
Naked mole-rats are extremely social creatures, living their entire lives in highly-structured colonies. They don’t take kindly to strangers or enemy colonies, so it’s vital they know who’s part of their group and who’s not. One way they do this is by rolling in their own feces or the feces of their comrades, so everybody smells the same. But naked mole-rats also use sounds to interact with each other – chirps, grunts, squeaks, and squeals.
Researchers have recently discovered that the noises naked mole-rats make aren’t random. A group of neuroscientists used machine learning to analyze over 30,000 “soft chirps” from seven naked mole-rat laboratory colonies over two years. They found that each colony had a unique sound, varying in frequency.
Naked mole-rats learn these chips when they’re young. They also learn how to ignore foreign dialects. The naked mole-rats in the study even responded to artificially-constructed chirps intended to match the dialect of their colony. That means that they recognize a particular frequency, not just the voices of other mole-rats they’ve heard before.
Interestingly, the researchers also noticed that dialects played a role in a colony’s overall cohesion. When a queen died or wasn’t yet replaced, the colony’s dialect would become variable, as if the colony as a whole lost its voice. Once a queen was firmly in place again, the colony’s dialect became clear and distinct once again.
Why Are Naked Mole-Rats “Naked?”
Naked mole-rats live in semi-arid desert regions that can become very warm during the day. Not having hair or fur keeps them cool in the daytime. At night, if it gets too cold, they’ll all huddle together in a pile to keep warm.
Naked mole-rats aren’t completely hairless, however. They have about 100 tiny hairs all over their body, which they use to help them feel what’s around them. The hairs between their toes help them sweep soil behind them as they tunnel and dig.
Can You Keep a Naked Mole-Rat as a Pet?
Naked mole-rats aren’t domesticated, as it’s hard to maintain the conditions they prefer. They have specific habitat and temperature needs that can be hard to replicate at home. Several zoos throughout the world have naked mole-rat exhibits, but these zoos typically have the resources to build an adequate habitat for naked mole-rats. Having a naked mole-rat as a pet is generally not advised.
Final Thoughts on Naked Mole-Rats
Naked mole-rats are fascinating, bizarre creatures that continue to surprise scientists. The more we study these underground rodents, the more odd facts we learn about them. These unique animals will likely keep us interested for a long time!