A swarm is usually a job for a beekeeper.
A cluster of bees hanging on a branch, fence or wall is a swarm resting while it looks for a new home, and it often moves on by itself. Leave it alone and don't spray it. Apiculture New Zealand lists swarm collectors by region, so a local beekeeper can come and collect it.
If the bees are going in and out of a gap in the house, choose that answer instead: that one is a job.