The most common insect pests in Western Washington are subterranean termites, carpenter ants and powder post beetles.

Unlike other pests of the country, termites do not pose a serious threat. Entry into a home is typically where soil may touch the wood. Maintenance of these areas is often attended to for the prevention of dry rot and thus termite infestation is prevented as a result.

Contrary to popular impression, termites are very slow eaters. A mature, well-established colony of 20,000 workers eats only a fifth of an ounce of wood a day. Carpenter ants pose a problem not because they eat wood, but because they remove quantities of it to expand their nesting facilities. Most carpenter ant species establish their initial nest in decayed wood. The parent colony is often located in a tree, stump or in stacked wood within 100 yards of a home. A number of workers from these parent colonies will frequently move into a dwelling as a satellite colony. During the first warm days of spring (January - June depending on location) these reproductives emerge from their rest period for their mating flights. After mating, the males die. The inseminated queen selects a nest site, usually in a small cavity or in the timbers of houses, and within a few days lays her first eggs.

It is important to determine if an infestation of carpenter ants is actually present, as ants may enter houses while foraging or new queens may enter homes after nuptial flights and may not actually be causing problems. Where carpenter ants are common, the wall voids of a new structure may be dusted with boric acid. This material, if kept dry, will kill the ants if they enter the void. This treatment provides control for up to 20 years.

The presence of powder post beetles is often indicated by a fine almost talc like powder accompanied by small holes the size of pinheads. The infested wood has a dull, soft sound when rapped with a hard object. Extensive damage can occur if an active infestation is allowed to spread. The infected materials should be treated to exterminate any existing pests and sealed to prevent reinfestation.