Carpenter bees look like bumble bees, except for the yellow spot on the face and the knife-like mouth parts. Carpenter bees, unlike all other bees, rarely hurt people but do major damage to physical structures. They drill 1/2″ holes in wood, going in about an inch and turning with the grain to tunnel about 12″ to make development chambers for their young. There is a theory that they will not attack painted wood (see photo below). General spray rarely controls them. Each hole must be treated with something that will kill the bees which are home now and will last to kill bees which will arrive later. Pricing depends on the extent of the infestation. The earlier we get at it, the lower the price.
First you notice the shavings, looking like saw dust. Then you see the holes.
In the holes are larvae, which rarely emerge as larvae.
These two responded to pesticide by exiting the holes.
When the larvae pupate and emerge as adults, they can do more visible damage.