How does the colony decide to split?
Pheromones, otherwise known as chemical messages. Bees use many pheromones to communicate different messages throughout the colony. The queen releases pheromones from mandibular glands (adjacent to the jaw line), which are passed to her worker bees through feeding. Her pheromone “cocktails” can instruct worker bees to collect food, create swarming cohesion, and prevent the maturation of eggs in other female worker bees. This form of communication unifies the colonies survival tactics. One mode of survival is reproducing the hive, and this happens when the colony has become so large that some of the worker bees are not feeding the queen and thus not receiving her pheromones. Such a population believes there is no queen, and begins raising a queen of their own. The existing queen must leave before the virgin queen emerges from her cup.
Meanwhile, the “old queen” is trimming down and sending out scouts to find a location to cluster. The cluster location isn’t far from the hive, and the swarm will only cluster as long as it takes to find a new nest. So, if you happen upon one, you are one lucky individual to be witnessing such an important part of a hive’s life cycle. Enjoy the view!
During the cluster some of the best foraging bees are sent out as scouts to find the next nesting site. Upon returning to the cluster, the scouts will do a waggle dance. The degree of enthusiasm the bee is waggling will encourage other scouts to verify the nesting site is indeed a good one. Finally, the entire swarm will leave together to begin building their new home.
What should you do if you see a swarm?
Please do not be afraid, but do show respect. Bees are not in the mood to attack at this very vulnerable moment in their life cycle. Stand back, give them space, and watch. If you are concerned, contact your local beekeeping association for a list of bee rescue contacts. Do not exterminate bees, they are critical to our survival!