Powderpost beetles
The adults are very small, less than 1/4″ in size. They are flattened and reddish-brown to black in color. Larvae are white, cream colored, shaped with dark brown heads. Larvae create tunnels in the wood and become pupae. As adults they bore out through the wood, pushing a fine powdery dust out. The shape of their holes are round ,about 1/32-1/16 pinholes.
The term “powderpost” comes from the fact that the larvae of these beetles feed on wood and, given enough time, can reduce it to a mass of fine powder. They are therefore considered pests. The family Anobiidae is the only one capable of digesting cellulose, the primary ingredient of wood, and all other species excrete the wood without digesting it.