Chinchilla rats have large, round ears, large eyes, and an elongated head. They have short legs with four toes on the front feet and five toes on the back feet. The head and body length of the chinchilla rat is 6 to 10 inches (15 to 25 centimeters with a tail length of 2.4 to 7.2 inches (6 to 18 centimeters). They weigh from 7.1 to 10.6 ounces (200 to 300 grams).

The fur of the chinchilla rat is thick and soft. Fur coloring is silver-gray or gray-brown on the upper body and light brown, cream, white, or yellow on its underside.


They are found from coastal areas to the Andes Mountains in southern Peru, northern Chile, northwest Argentina, and central Bolivia.


Chinchilla rats live in rock crevices and elaborate burrows under rocks or at the base of shrubs.


Chinchilla rats are herbivores, meaning they eat only plants. The feed at night on seeds, fruits, and nuts.


There is very little scientific information on the behavior of chinchilla rats, due to their small population. Only a handful of research has been done on the small rodents. What is known has usually been gained by observing the behavior of only a few of each species.

Chinchilla rats live inside burrows in colonies of up to six individuals. Colonies are usually close together, sometimes as little as 59 feet (18 meters) apart. Little is known about the reproductive behavior of chinchilla rats. They usually mate in January or February. The gestation period, the length of time the female carries the babies in her womb, is 115 to 118 days. Litters are usually one or two babies.

There are four species: Bennett’s chinchilla rat, which lives in the coastal foothills and high plains of the Andes Mountains in Chile; Bolivian chinchilla rat, which is found in central Bolivia; ashy chinchilla rat, found in the high plains of the Andes in Bolivia, Chile, and Peru; and Cuscomys ashaninki, which does not have a common name, found in Peru.

Cuscomys ashaninki was discovered in 1999 when a single dead body was found. As a result, there is virtually no information available on this species. The skeletal remains of another species, Cuscomys oblativa, have been found in Peru but the species is believed to be extinct.

Bennett’s chinchilla rat sometimes shares burrows with similar-sized degus. A Bennett’s chinchilla rat in captivity lived two years and four months. Their lifespan in the wild is believed to be one to two years.


Chinchilla rats are sometimes hunted by humans for their fur, which is sold at local fur markets and has a low value. It is sometimes sold to tourists as real chinchilla fur. They were hunted extensively for their fur in the early twentieth century and all species were nearly extinct by the 1920s when several South American countries passed laws to protect them.


The Bolivian chinchilla rat is listed as Vulnerable, facing a high risk of extinction in the wild, due to its population being confined to a small area. The other chinchilla rats are not listed as threatened by the IUCN.