Cryptomys hottentotus
African mole rat

Common mole rats are found in southwestern Cape Province, South Africa.

Common mole rats live in the soil of grassy open plains.

Body length of common mole rats ranges from 10.5 to 16.5 cm long and tail length from 1.2 to 3.8 cm. The fur is thick and is composed of many different colors, including a white spot on the head. Many of the physical features of mole rats are suited to an underground lifestyle. The body is cylindrical and the appendages are short. This shape allows the animal to burrow effectively. Long sensory hairs called vibrissae stand out from the pelage over the body. Mole rats have chisel-like incisors used for digging. The eyes are very reduced. In each colony, the reproductive male and female are the largest individuals. The rest of the colony members exhibit a sexually dimorphic pattern of size where the males are larger than the females.

Common mole rats live an entirely subterranean life. They dig extensive tunnel systems, one tunnel system, which contained 10 adult and 3 young, measured 1 km in length. The tunnels are dug mostly through compact soils but occasionally sandy soil is used. The tunnel systems are primarily a product of the search for food, but they also provide sites for food storage, nesting and waste disposal.

Common mole rats are social creatures, living in family units of up to 14 individuals. Each colony has one reproductive pair, which are usually the largest female and male in the group. The other individuals in the group are workers. The creation of a caste system of workers and reproducers is an example of eusocial animal behavior. The dominance hierarchy in a common mole rat colony is described as linear. The breeding male is at the top of the hierarchy, followed by the breeding female. For the rest of the colony males are dominant to females, and dominance is related to body mass.

The worker category is divided into two groups of animals, the "workers" and the "casual workers". The worker group usually consists of smaller sized mole rats that have been newly recruited to the colony. These mole rats do 15-20% more work than the second group, the casual workers. The casual worker group is comprised of larger, older mole rats.

It is very difficult for researchers to capture all of the members of a particular tunnel system. Because of this problem, little is known about how members of C. hottentotus get to be reproductive individuals in a given community.

Common mole rats are herbivorous, eating mainly geophytes, plants with underground storage organs, and grass rhizomes. They also consume large quantities of fiber, found in the roots of many plants.

Common mole rats can cause damage to human property. They can eat through most anything, including underground cables and roots of crops. The large mounds of dirt that they dig up can also cause damage to harvesting machines.

Due to the number of tunnels and amount of soil mole rats move, they help to improve soil drainage and soil turnover.

Though common mole rats are found only in Southern Africa, the population there is quite dense. Mole rats have few predators due to their fossorial lifestyle and the lack of ground burrowing predators in Africa. The eastern beaked snake and some birds of prey may attack mole rats while digging out a burrow or venturing to the surface. Mole snakes (Pseudaspis cana) prey upon mole rats by penetrating the tunnel system.

Common mole rats coexist in the same geographical location with two other genera of mole rats, Bathyergus and Georychus. This is possible because members of each genus burrow at different depths and vary in diet. This is unusual for burrowing animals, typically one burrowing species occupies a geographic range almost exclusively.

Longevity in C. hottentosis is not well known, three specimens lived for five years after capture.