They also ruined the best bluebird box that I ever had. It was in a prime location and the bluebirds loved it for year, until the carpenter bees found it. I tried sealing the hole with Gorilla Glue and a piece of wood, but they just cut another hole! Dang!
Next time, when I replace the box, I'm going to paint it with Drylok. Maybe that will deter them into thinking it's not wood.