They gather for battle orders around the outside light at the top of the alleyway between the buildings and make a sound like the rumble of military cargo planes lining up on a runway. You really don't want to get stung by one, either.
But with the turn of the seasons and the first icy temperatures in Provence, their time in the sun is over. Rather satisfying to see the source of the trouble close up knowing it's harmless now. What on earth we can try next year to control them and all the other hedonistic species of wasp determined to have the swimming pool is still unresolved.