Carpenter Bees
Carpenter bees (sometimes called "wood bees" or "borer bees") are large, stout bees that look quite a bit like bumblebees. You often can observe them chasing each other around during their mating rituals in the late spring and early summer, or see females hovering around exposed wood looking for appropriate places to build their nests.
Carpenter bees actually have some endearing qualities. They are industrious pollinators. They are non-aggressive and very rarely sting. They also are fairly attractive, as insects go. In fact, most people would probably like carpenter bees just fine if it weren't for their one annoying habit:
Carpenter bees drill holes.
Carpenter bees drill holes in wood wherever they can find it. They drill holes in house siding. They drill holes in fascia boards. They drill holes in soffits, swing sets, door and window frames, wooden statues, decks, banisters... Basically, anywhere carpenter bees can find a piece of softwood, they drill holes.
And to make matters worse, carpenter bees seem to take special delight in drilling holes in places that humans can't reach, such as behind siding and along roof fascia and soffits. Wherever they drill holes, they create sawdust and leave behind unsightly stains known as ejecta.