Fact Sheet : NAKED MOLE-RAT

 

A colony of
naked mole-rats



Naked Mole-rat
exhibit,
Fragile Desert

 

Order: Rodentia
Family: Bathyergidae

What do naked mole-rats look like?

Naked mole-rats are 7 to 8 cm long, with a 1 cm long tail. They weigh between 25 and 40 g. They have little to no hair throughout their body. Their skin is wrinkled and pinkish or yellowish. Their eyes are very small and barely used for sight. They have very small external ears and a good sense of smell. They have very noticeable front teeth that stick out beyond flaps of skin that close off the rest of the mouth. Their nose opens directly above their front teeth, but a skin flap protects it against sand and dirt.

How do naked mole-rats move and communicate?

They walk on all four feet. They can move backward as quickly as they can move forward and can even somer-sault in tunnels. A naked mole-rat honks or squeaks when it is disturbed.

Where are naked mole-rats found in the world?

Naked mole-rats are found in arid regions of central and eastern Ethiopia, central Somalia, and Kenya. They live in underground colonies with extensive and complex burrow systems, in hard clay soil. At Brookfield Zoo, you can find them in The Fragile Kingdom Desert.

What kind of behavior do naked mole-rats exhibit?

Naked mole-rats are active early in the morning and in the late afternoon to avoid extreme temperatures near the surface. Most digging is done after rain. Naked mole-rats live in well-organized colonies, with up to 100 members in a group, but 20 to 30 is normal. A dominant female (the queen), who outweighs the others by up to 20 g, leads a colony. The queen will leave her nest chamber to check on her workers. Workers cooperate in burrowing, gathering food, and bringing nest material to the queen and nonworkers. They use their teeth to chisel earth and create piles of soil. A worker uses its legs to kick soil backward through the tunnel. At the end of the tunnel, it gives its soil to another worker, which kicks the soil out of the tunnel. The worker then crawls back into the tunnel, over the others, to dig again. The larger, nonworker soldiers defend the colony.

How does a queen lead her colony?

The queen rules by her behavior and possibly by chemicals called pheromones that are let out in her urine. When she dies, several of the larger females fight, sometimes to the death, to become queen.

Living underground, what do naked mole-rats do about waste?

Naked mole-rats use a separate central toilet area. Since they pass through this common toilet area, walking on urine and feces, everyone has a common smell. They do this to recognize members of their own colony. If an outsider enters the colony, they fight fiercely.

How do naked mole-rats reproduce?

Males and females are ready to breed at one year of age. Females are pregnant for 70 days. A litter is usually between three and 12 pups but may be as large as 25. The queen is the only female that breeds, and she breeds with one to three males. In the wild, naked mole-rats usually breed once a year if the litter survives. In captivity, they breed all year long. The young are born blind and weigh about 2 g. The queen nurses them for the first month, then the other members of the colony feed them feces until they are old enough to eat solid food.

What do naked mole-rats eat?

In the wild, they eat roots and tubers, leaving enough root behind so that the tubers grow back the following year.

Who are naked mole-rats’ predators, and what is their defense system?

Their predators are snakes. Large “soldier” mole-rats move rapidly to a point of disturbance and fight off the predator with their large incisor teeth.

What is their status in the wild?

Naked mole-rats are highly successful in the wild, with no danger of extinction at the present time. They are considered pests in some areas as they will eat the roots of a farmer’s crop. They also do well in captivity.

What kinds of things will I see in the exhibit?

You can get right up to the front of the exhibit, so you’ll have no problem seeing the animals. You won’t be able to hear the naked mole-rats since they’re behind glass. You probably won’t be able to recognize individuals, except perhaps the queen.


Continue your research!

Read about naked mole-rats up close! There's a fun article called "Not Just Another Pretty Face" on the Wildlife Conservation Society site.

Check out the Mole-Rat Cam hosted by the National Zoo of the Smithsonian Institution.

Find a lot more animal and zoo sites on the Links Page!

 

You can also go back to the animal list.

Images © 1997, 1998, 1999 Chicago Zoological Society. Brookfield Zoo is owned by the Forest Preserve District of Cook County and managed by the Chicago Zoological Society.