Don't Panic, swarming bees are usually good tempered.

If the swarm is not causing a nuisance then leave it, gradually the bees will cluster in a bush or tree and remain there for ashort time. During this time scouts will look for a new home, the only problem may be they may choose places such as your chimney or eaves of your roof. If the swarm is a nuisance then the council keep a list of local beekeepers who can help.

Beekeepers that will collect honeybee swarms in Belfast