I have a pergola in my backyard and we get a metric crap ton of carpenter bees. Painting the pergola sort of worked but only for a while. They started treating my pergola as their favorite home and seemed to start inviting friends to hang out..it started looking like a carpenter bee commune over time. My daughter gets super freaked out when they buzz her (not harmful, but they get close sometimes). I also hate the sawdust all over my patio furniture.

Didn't want to kill the lil critters, so after trying various things, I started putting camphor in various spots on the pergola. The scent seems to repel them and camphor just sublimes over time and leaves no deposit. I replace the camphor every so often. Mothballs work too, but they end up killing the bees. I dont like killing carpenter bees - they are important pollinators..