The natural nesting site of the honey bee is a sheltered, darkened enclosure. Beekeepers keep their colonies in boxes called hives.
Bees also nest in tree hollows and dry caves.
Whether living in a hive or the side of a building, when a bee colony becomes too large it divides by swarming. A honey bee swarm contains thousands of workers and their queen. A swarm of bees will cluster temporarily at one location while a few scout bees locate a new home. When a suitable location is found the swarm moves as a group into its new quarters. Bees nesting in locations inconvenient to humans are considered pests.