Every spring, carpenter bees come out in full force. They are making their home under the eaves of my roof. Where do they go in the winter? And is now a good time to get up into the attic and find their nests so I can exterminate?
Carpenter bees get active in the spring. That said, now is a good time to find and plug the holes they make. If not, they will come back to those same holes next year.
Another option is to replace the wood trim with a material they can not eat like Azek. I replaced all my facia on the my garage with this after several bad carpenter been years and they finally gave up and went somewhere else for meal!