woodpecker

[40north]

View attachment 330922
https://www.amazon.com/Sunnyside-corporation-76904M-Advanced-Insecticide/dp/B01FWIP112
I never would have thought woodpeckers and insects could be so destructive.
I had a roach problem in my kitchen. I sealed and patched every hole, opening, crack, and crevice, and then I painted the insides of my cabinets with paint that I added this to. It worked for me.
I'll bet it would work on carpenter bees.

MSDS> https://www.sunnysidecorp.com/pdfs/SDS_76904M.pdf
Insecticide fraction> https://en.wikipedia.org/wiki/Deltamethrin
Bees + Deltamethrin> https://www.beesource.com/threads/deltamethrin-usage-near-bees.274832/