Wasps are the Good Guys, so we've not been bothered by the nest behind our neighbours sofit, despit it being in close proximity to our back bedroom-cum-office window. Recently we've found the odd one crawling around in the house, probably coming in via the bathroom velux. Then, one morning recently, there were maybe a dozen crawling up the back window, leaving some residue behind, but that only happened the once.
To this morning, I'm in the kitchen making tea about 6:30, and I hear the kind of "tick-tick" noise we get from our neighbours conservatory roof when it rains. This was unexpected so I glanced at the (half-glazed) back door, where there were maybe 100 wasps crawling on the glass, the ticking being them impacting it. I assume they were heading for the light, but it was a bit disconcerting!