Mastotermes is the most primitive of termites, sharing characteristics with the Cryptocercus wood roaches, social cockroaches that share a common ancestor with all termites. Several extinct species of Mastotermes are known from the fossil record. Many extinctions are relatively recent, occurring several million years ago. The northern Australian species, Mastotermes darwiniensis, is the only extant species.
Like Cryptocercus, Mastotermes makes nests by chewing galleries in wood. Colonies are usually small but under ideal conditions may produce millions of individuals. A colony typically inhabits a single piece of wood but will forage on plant material outside the nest and may connect several pieces of wood with galleries. This type of nest places foragers closer to their sources of food. In some regions of Australia, Mastotermes makes vegetable production unprofitable due to extensive foraging Mastotermes colonies can kill a tree by girdling it at its base. The colony then builds a nest in the center of the dead tree.