What Attracts Carpenter Bees to Your House?

Carpenter bees don't eat wood — adults feed entirely on nectar and pollen outdoors — so any wood they excavate is purely a nesting site, and the deciding factor is how easy that wood is to tunnel into. University of Maryland Extension, Ohio State University Extension, and Purdue Extension all describe the same strong preference: bare, unfinished, or weathered softwoods such as cedar, redwood, cypress, pine, and fir are excavated readily, while painted or pressure-treated wood is rarely attacked at all.

That single distinction explains most of the pattern people notice around a house. Sun-exposed, unpainted surfaces — the underside of eaves and fascia boards, deck railings, unfinished trim, old fence posts — are the classic starting points, often beginning at an existing nail hole, crack, or old bee hole from a previous season. A neighboring house with the same style of construction but a well-maintained paint job on its trim can see far less activity, simply because the surface itself is a much weaker nesting cue.