These are generally dark beetles, small to very small. In many species, the head is more or less hidden by the wide pronotum whereas in others it lengthens into a kind of rostrum which makes them look like snout beetles. In fact, most beetle experts now consider the bark beetles and ambrosia beetles to be subfamilies of Curculionidae. In the very great majority of the species, all the development and the existence depend on the presence of deciduous trees or conifers. Scolytids secrete pheromones, odorous substances nonperceptible by the man, which are used for aggregation or to attract a potential mate.
They develop in the bark (corticolous) or wood (xylophagous) of trees. The females dig a maternal gallery from which the larvae drill their own tunnel which deviates some on each side in general. Bark beetles are great pests of forests.