Vigilance and attentiveness is definitely better here; early in the year you are looking for a handful of wasps spending more time near any one part of the faca

Vigilance and attentiveness is definitely better here; early in the year you are looking for a handful of wasps spending more time near any one part of the facade of your house than normal. Pick a warm day in mid-spring, go round the property and note where wasps are going. You can safely use a spray to pick them off late in the evening, and if you get there early enough, depending on the species, one of those wasps could actually be the queen, because she may still be leaving the nest in order to care for her earliest brood. If you don't get the queen, because the nest is so small, you may get enough toxin onto one of the early workers that they will bring it into contact with the queen. You then use an insecticide foam around the entrance to any hole you see wasps going into. You can lay it on pretty thick, more than once, and they will progressively poison the nest. You can do this a few days apart in the evening. Since the nest is still small you probably don't need to hit the nest, and you might as well leave it because then no other colony will use the space. You do need to saturate any pathway they take to it. Directly above a bedroom window that is impossible to see from the outside but can be deduced by a process of elimination, in the roof of my 210 year old house, is a tiny gap, which attracted a nest nine years ago. I used this method and while I think I might very well have got the queen directtly, activity around the nest stopped in about 48 hours, and while every year I see wasps investigate the hole, I am guessing corpses put them off. In the warm late spring of the pandemic I resprayed the hole, and sprayed a couple more, with what was left of the can, because I reasoned that it might be difficult to get a pest controller to deal with them; this proved to be a wise decision because nests established in several places nearby in that lovely hot summer that went untreated for far too long.