Honey bees often swarm in the spring and early summer when their population increases rapidly and conditions inside the hive become too crowded. Prior to swarming, the bees will gorge on honey to fuel their flight. Then the queen and half the bees will take off in search of new digs. But before the swarm makes it too far from the hive it will take up temporary residence on something nearby - a bush, a tree branch, a picnic table, a fence, etc. - clustered together with the queen inside. The cluster of bees will stay put for a few hours up to a few days while scout bees search for a new home.

From the beekeeper's perspective, swarming is considered something to avoid because it drastically reduces the number of bees available to make honey. Some beekeepers who aren't as interested in harvesting honey but keep bees more for pollination services may view swarming as a helpful self-thinning event. But if the swarm leaves later in the year it can leave behind a colony too weak to make it through the winter. Ideally beekeepers try to prevent swarms.