About 250 species are known from our region and some 2500 for the whole world. Larvae, with few exceptions, feed primarily on insects destructive to bark and wood, such as the larvae of bark beetles and longhorned beetles. They are generally considered important in the natural control of forest pests. Hister beetles-Family Histeridae. Many have very obvious forward-projecting mandibles.
Different species occur in different habitats.
Some frequent carrion, dung, or other rotting organic matter where they are predaceous on scavengers such as maggots. Other species are found under the bark of trees or in burrows of wood-infesting insects. Their most important role in biological control is probably as predators of wood boring tree pests and filth flies. The larvae are also predators. More than 3,000 species are known, with 500 in North America.