Figure 16.

Naked mole-rats, which live underground in East Africa, are among the most unusual mammals in the world, almost hairless and almost blind, with only one reproductive female and several reproductive males. Other colony members specialize in colony tasks and do not reproduce; the caste system has been compared to eusocial insects, which also have nonproductive workers. This small group of nonreproductive workers was collected by a researcher in East Africa whom we encountered on a dirt road, where he was capturing workers that appeared at the surface while excavating cavity tunnels. They are caught by snakes in the same way, as they emerge at the surface. A colony may comprise 80 individuals, or sometimes up to several hundred, and feed on plant roots and tubers underground. This diet is high in cellulose, which is difficult to digest. Their gut microbiota help with digestion, and coprophagy (ingestion of feces) allows maximal extraction of nutrients.