IMG_2650Swarms are the honey bee’s way of creating new colonies. A new queen is produced in the old hive/nest, and the existing queen will swarm with all of the flying bees to create a new colony in a new location. The size of this swarm will vary, a good swarm will be the size and shape of a large rugby ball, a cast or secondary swarm may only be the size of a grapefruit. Immediately after they leave the original hive, they will sometimes swarm to a nearby location, and this is why you will often see them hanging from a tree or bush, while the scout bees find a suitable home.
The swarms will only inhabit a location that is large enough for them to grow to a healthy size. They will not take over your bird box (unless you built it to house an eagle) those will most likely be Bumble Bees. They might however choose your empty compost bin!