Bees swarm when going out to start a new hive. A swarm may contain from 1,500 to 30,000 bees including, workers, drones, and a queen. Swarming is an instinctive part of the annual life cycle of a honey bee colony. It provides a mechanism for the colony to reproduce itself.
When honey bees swarm they will settle on a tree limb, bush, or other convenient site. The cohesiveness of the swarm is due to their attraction to a pheromone produced by the queen. The swarm will send out scout bees to seek a cavity to nest in and will move on when a suitable nesting site is found. Rarely, swarms may initiate comb construction in the open if a suitable cavity cannot be found. You may want to call a local beekeeper to see if he would like to collect the swarm. Contact your county extension office or the Nebraska Department of Agriculture for a list of beekeepers in your area. Late season swarms are of little value to beekeepers.
Overcrowding and congestion in the nest are factors which predispose colonies to swarm. The presence of an old queen and a mild winter also contribute to the development of the swarming impulse. Swarming can be controlled by a skilled beekeeper; however, not all colonies live in hives and have a human caretaker.
Honey bee swarms are not aggressive.