I had a nest of small bees behind some outdoor steps.. Could not get to the actual nest. I could see the opening between pieces of the wood steps where the bees went in and out. First attempt was to use popsicle sticks to "spoon" some Sevin dust into the opening. I think it slowed things down but not completely gone. Next was an aerosol can of termite and carpenter bee spray. It's got a 8" flexible hose and foam comes out. Squired that into the opening at 4 AM and that was the end.