I live in a condo (end unit townhouse). There is a slanted wood trim
near the roof on the side of the building. There is a gap behind the
wood trim and wasps (yellowjackets) have been flying into the gap
behind the wood trim and building nests there. Although I wasn't
aware of this at first, my impression is that they have been nesting
there every year. I've been here almost 4 years.

If they haven't gotten inside the building or bothered anyone, are
they best left alone, or does leaving them alone typically lead to
them causing damage?

Seems to me the only permanent solution would involve screening off
the gap, but the wasps would need to be exterminated first, and one
would have to be very certain they are all dead before screening off
the gap. Should I insist this be done, or are they best simply left
alone?

Thanks,

Jay