Bees are among the most essential of insects because of the crucial role they play in pollinating many of the plants that are important food sources, but the sight and sound of them buzzing around can sometimes make people anxious. Seeing swarms of bees might sound alarming, but swarming is a normal part of honeybee behavior and does not typically pose any risk to people.

Honeybees are the only type of bee that swarms, and the bee swarms most commonly occur in spring. Swarming, as the behavior is called, happens when a colony gets too crowded. The queen in a colony begins laying eggs in the winter, and as the eggs hatch the nest gets too full, according to the University of Georgia Extension. When this happens, the colony will raise a new queen, and the original queen will leave to establish a new colony, taking half the bees with her when she goes. It's that group of bees on the move that creates a bee swarm. 

A swarm can include hundreds or even thousands of worker bees, along with a few drones and one queen, according to Iowa State University Extension and Outreach. As the swarming bees split off from their existing colony, they will fly around for a brief time before selecting a spot to collectively gather.

Tree branches or trunks are frequently chosen as a gathering spot for the swarm, but any suitable nearby location can be selected. The swarm can cover an object or create a hanging ball that can be about the size of a basketball, the Georgia Extension reports. 

Once the swarm has settled into its temporary spot, bees called scouting bees will leave the swarm to look for a location for a new hive. They may remain clustered at their temporary site for between a few hours to a day until the new hive site is selected. The bees will typically move into their new hive in clusters instead of in one large swarm, according to the Iowa State Extension. 

Because the honeybees in a swarm are not defending their hive, they are typically gentle, and the risk of being stung is low, according to the Purdue University College of Agriculture. Because of this, a bee swarm is in most cases no cause for alarm and does not require intervention. Some exceptions to this are swarms in a busy public space and those that pose a risk to people or animals or that are in a vehicle or interior of a wall. 

The Will County Beekeepers Association maintains a list of beekeepers who can be contacted for removal of bee swarms. As a last resort, bee swarms can be sprayed with soapy water to kill the bees. However, this can be dangerous because of the number of bees in a swarm and their ability to sting, the Iowa State extension reports.