Last year, I was aware of a strange buzzing sound when using the shower cubicle.
Then we realised that there were wasps coming-and-going from the extractor vent outlet - obviously they'd built a nest in the extractor pipe.
That's a particularly unpleasant idea, being naked in the shower and lots of angry wasps coming in through the vent...
We had some ant powder in the garage, so I went up the ladder with a towel round my head and puffed the ant powder over the vent - the container said that the idea with ants is that you put it at the entrance to the anthill, the ants walk through it and it sticks to them, they carry it into the nest - I reckoned it would have the same effect as the wasps landed on the vent grille.
Despite me being up a ladder next to the vent and puffing this stuff about, the wasps didn't bother me at all, no attempt to attack me.
And a couple of days later they'd stopped coming and going.
Except that we then became aware a week or so later that they - or another lot - were nesting in the roof, coming and going through the soffit. So repeated same ant powder trick, again they went away/died off.
Job done, I forgot about this until we had a bloke doing a bit of pointing and tile-fixing on the roof. Suddenly there was all sorts of loud panicky swearing and he came clattering down his ladder - apparently had removed a tile and come face-to-face with the waspnest, not realised it was a 'dead' one, throught he was going to get a faceful of wasps...