So you think you have a swarm of bees?
Don’t Panic, bees in a swarm are universally in a good mood. They can not easily sting even if antagonised as they have gorged themselves with honey and can not get their bodies into the best position to sting.
If the swarm is not causing a nuisance it may be left, gradually the bees will cluster in a bush or tree and remain there for up to 3 days. During that time scouts will be sent out to look for a new home. Bees are easy to recover in a swarm cluster but if left may home in on a roof cavity, chimney or similarly inaccessible space where they become a nuisance.