Posted: 03/07/2014 at 18:36
As a beekeeper I feel I can answer this. Honey bees swarm when their colony has become too large for their home, whether it be a hive or eg tree stump. The colony make queen cells from which obviously new queens are hatched. As soon as the workers seal the queen cells, the old queen takes off with approx. half of the colony to begin a new colony elsewhere. Sometimes a lucky beekeeper catches the swarm (a free colony for him/her) sometimes they take up residence elsewhere. I have to say that a swarm of bees is a truly lovely sight as they are doing what comes naturally to them. I know they look alarming but they are only interested in finding a new home.