What is the swarm of bees doing?
A bee swarm is a term for when the bees are not living on honeycomb in a colony but are on the move, they are often found in the form of a mass of bunched up bees on top of each other often hanging from a branch of a tree but this can also be on the side of a building too. The bees are normally just stopping off before they get to their desired new colony location where they will make honeycomb and live for many years.
Now, private bee keepers can help but not normally immediately and it can be a massive risk leaving the bees to go where they fancy when on your land. They may just end up flying off but they could also end up deciding your chimney or property roof is where they want to live. If this happens it will be a challenging and costly location to remove them from.