Wood-eating insects, in addition to the damage they cause to nature, are also the most important enemy of raw and treated wood. They belong to the classes of: Coleoptera, Hymentoptera and Isoptera. In the first two classes belong the insects that are commonly called "wood worms" while in Isoptera belong the termites.

These insects lay their eggs somewhere in the wood while after about a month the larvae enter the wood. The larvae can remain in the wood for several years, where they feed on the components of the wood. When the time comes to mature, they sit under the surface of the wood for about a month and transform into mature insects, then make a hole in the wood and fly into the environment, where they find their mate and the new biological cycle begins.

Characteristic of the presence of wood-eating insects is the fine dust, frass , which falls from the holes in the wood and consists of wood shavings mixed with insect feces. We examine this dust and from the shape of the feces we know the type of insect from which the dust comes.