We once rented a cabin off-season in a ski resort area. Being off-season, the cabin hadn't been used for a while. Seemed fine until groggy wasps started coming out of a floor heating vent. Turned off the heat, got the vacuum cleaner and put over the vent. Turned it and the heat on and left it run until no more pings of wasps getting sucked in.

Warned the maid that the vacuum was full of wasps. She barely spoke any English and looked at us like we were crazy.

Never heard what happened when she went to empty the vacuum.