European wasps are the summer emergency. A nest the size of a golf ball in November is a basketball by March, and they sting repeatedly rather than once. They nest in the ground along fence lines, in wall cavities, in compost heaps and under eaves, and the season peaks February to April. Do not block the entry hole yourself, because that drives them through the cavity into the house.
Honey bees are a different call. A swarm hanging off a branch is house-hunting and usually moves on within a day or two, and a local beekeeper will often collect it for nothing. Treatment is for colonies inside a wall or roof where someone is at genuine risk. Where a hive has been in a wall a while, the comb and honey have to come out or it ferments through the plaster.
