The most well-documented and encountered bee swarms are those of honey bees. Typically, honey bee swarms are not a major threat, unless when dealing with Africanized honey bees. The bees do not have a nest or young and, therefore, are less defensive. However, they will sting if provoked.
Bee swarming typically occurs in colonies that are thriving and with robust populations. Weak colonies of bees may not swarm until they become stronger and larger in population. Bee colonies may become weak due to starvation, disease or failing queens. Several factors can contribute to the occurrence of a swarm, such as seasonal changes and overcrowding.
Swarming involves a contingent of workers and a queen departing the original colony. The swarm typically gathers at a resting site, often in a tree, after leaving the colony. Scouts are sent to location a new location, such as in a log or other cavity. Once a suitable location is found, the swarm will relocate to the site and begin to nest.
Two kinds of bee swarms occur: primary and secondary. The queen bees lead primary swarms, which include a larger number of workers acting to protect the egg-laying queen. Secondary swarms are led by several virgin female bees and as a result, these swarms are half the size of the primary swarm and do not occur as often.