When do bees swarm?

Bees swarm in late spring in search of a new home. During the winter the queen been being to lay her eggs and the colony sets about rearing it a young. As the weather becomes warmer and the early flowers appear, the raising of young bees increases rapidly.

By the end of spring the colony has becomes so overcrowded that a large number of the bees, including the old queen, live the hive and establish a new colony. In the old colony a new queen emerges who will experience the same swarming instincts the following year. And so the cycle of activity goes on.