The site of swarming bees can certainly be unnerving for many, but this is a fundamental and magical part of the life cycle of honey bees.

SWARMING IS THE COLONY’S NATURAL MEANS OF REPRODUCTION

During winter, bee colonies are small to conserve food and resources, often consisting of just the queen honey bee and about 10,000 to 20,000 workers. However, as the weather becomes warmer, the colony expands massively, producing more workers to perform a variety of jobs; foraging, regulating the temperature of the hive, guarding the colony, feeding each other, cleaning, creating wax, comb, and honey.

During all of this activity, the bees are communicating through pheromones that are produced by the workers, drones and the queen. These pheromones are passed through food sharing. So, in the act of feeding, the bees are also communicating with each other! This transferring of food from one bee to another is known as ‘trophallaxis’ and also occurs in other social insects. The queen honey bee’s pheromone attracts the workers to her and encourages them to forage, build the comb, and tend to the brood.

As the colony continues to grow by thousands, the crowd becomes so massive that not all of the workers have access to the queen, and therefore are not receiving her pheromone. Without her pheromone signals, the queen appears to be non-existent, inducing these workers the need to create a new queen. However, each colony has only one queen.

DIVIDE AND CONQUER

Before a new queen emerges, the old queen leaves the nest with part of her colony in search of a new location. You may see a whirling mass of swarming bees in the air (check out this video from our office), or a swarm settled on a tree branch or other location. This “clump of honey bees” is caused by the workers gathering around the queen. Since she is not the strongest of flyers, she will need to take a rest during their search for a new nest.

During this time, “scout bees” are sent out to look for a suitable location for the colony’s new home. When possible sites are found, often taking a few hours to a few days, the scouts will perform a waggle dance to tell the other colony members about their discovery. (See the dance about 3 minutes into this video). The members of the colony then debate the new location before making their decision.

IS THE SWARM DANGEROUS?

The bees are focused on finding a new nest and are not looking to sting you. However, they can become aggressive if they feel threatened. If the bees are not in an inconvenient place, it is best to simply leave them alone.

If you must remove the swarm, locate a local beekeeping group and contact them.
Do NOT spray the swarm with chemicals, throw rocks or sticks, or use any other methods of “bee control” that will likely provoke the bees.

Watch a video about bee swarms here.
Read more here.