What is a swarm and where did it come from
Depending on the weather Honey Bees will usually start to swarm around April and can do so up to the end of July, but it is known for them to swarm later than this. Swarming is a way for bees to increase and ensure the species which may have been lost through disease, colony collapse or by a very harsh winter.
A swarm is a complete colony of bees from a bee hive which may have become crowded, about half of the bees from the colony leave the hive with a queen, workers (female bees) and drones (male bees) as a frantic buzzing cloud, before leaving the hive they will have consumed and filled them selves up with honey as they will not know when they will next feed, this usually happens around mid-day when the cloud of bees will alight onto a nearby branch, fence post or onto the side of a building, the colony will then send out scouts to find a new home, which could be dark cavity in a hollow tree or wall, some have been know to find a compost bin as an ideal home, once found the colony will take off again in a similar buzzing fashion to their new home.
The remaining bees in the hive bring on a new queen which will secure the survival of the colony.
How will I know it is a swarm of honey bees
The swarm will usually alight onto a branch of a tree or bush in a tear drop formation, on a post the bulk of the bees will be at the top with thinning down the post with a few on the bottom of the swarm, if they settle on a cross rail of a fence or similar they will take the shape similar to half a rugby ball. Bees will be flying round the swarm coming and going until they cluster together for the night or if the flying scouts have found a new home they will take off.
It is at this time when they are on the branch or post the Beekeeper will be able collect the swarm, he will put them in a skep or cardboard box which will simulate a new home for them and they will not take off.
What should I do
When the bees left the hive they will have filled them selves up with honey, bees with a full tummy are much quieter and are usually only interested in finding a new home, this dose not mean they will not attach or sting you if they get disturbed or attacked they will become agresive and will most certainly attack and maybe sting you.
Ensure that they are honey bees as they could be bumble bees, once you have established they are leave well alone and contact a beekeeper my hot line is 07815 535488 who will advise you what to do and will either collect the swarm or direct a beekeeper to contact you.