We had a problem with bees/wasps one year in So. Calif. We had an above ground swimming pool, and this one year we were just dive-bombed every time we went near it. After mentioning it to the neighbor she said she had gotten an empty beer keg from someone that she was going to make something out of - - - it turns out, residue in the beer keg was calling them. We quickly solved that problem in that the keg was cleaned out and the hole plugged, and a happy ending. :-)
Marysewfun