Wood Destroying Organisms The most common wood destroying organisms in this area include carpenter ants, anobiid ("powderpost") beetles, and fungal rot.

Carpenter Ants: Look for large back ants. There is usually a "mother colony" in a tree, stump, log, or other piece of solid wood that could be several hundred feet from the house. They establish a "satelite colony" in the house, and begin chomping away on the structural members of your house.  The ants bring their brood (larvae) into the house for incubation.  Unlike termites, carpenter ants don't eat the wood, they only chew it away to create the tunnels or "galleries" in which they live.  They work slowly, but given enough time, carpenter ants can do severe damage to structural members.   

Most of the time, carpenter ant infestations are treated by a pest control operator, using the "drill and inject" method.  Fortunately carpenter ant damage is usually isolated.    

Beetles There are several wood-boring beetles in this geographical area, but the one of most concern is the anobiid (or "deathwatch") beetle. They are sometimes mistakenly called "powderpost" beetles, but that is a misnomer: anobiids and powderpost beetles are somewhat similar, but powderpost beetles are not found in this area.  Anobiid beetles are rarely found in newer structures, but are extermly common in structures that are more than 60 years old. 

To be a bit more correct, the beetles don't bore the wood, their larvae do.  The adult beetle lays its eggs on the wood, the eggs hatch into larvae.  The larvae chew their way into the wood, and spend the next 3 to 5 years tunnelling around inside of the wood, until they are ready to hatch into adult beetles, fly away, mate, and begin the process over.  Anobiids are most common in houses that are more than 50 years old, but are sometimes found in newer ones, too. When these guys are through with a piece of wood, you can crumble it into dust with your fingers, which is why they are often called "powder post" beetles (this is incorrect: powderpost beetles are similar, but aren't found in the Western United States).  

Termites    

Subterranian termites have been uncommon in Northwestern Washington, but seem to be  which are found here, but only very rarely.  Most of the termites in this area are "dampwood" termites. 

Dampwood termites are only found in wood that is wet enough to rot, so treating the termites is not necessary.  Just locate and correct the source of moisture, and the termites won't be able to live.  Of course, termite damaged wood usually needs to be replaced, as much because of rot damage as termite damage.