Why do Honeybees Swarm?
The queen is the only bee capable of producing eggs. For the honeybee to reproduce its species it is necessary for new queens to be produced to start a new colony.
Normally a queen produces a pheromone called queen substance which is passed round the workers and prevents them producing a new queen. However, if the queen becomes old or dies, or if the colony becomes very populous, workers receive too little queen substance.
In this case, they will then start to rear new queens. This often happens in late April, May or June. Once a new queen has been reared, the old queen leaves the hive with a proportion of the colony. This is a swarm.
The swarm often clusters on a branch. Scout bees fly out to seek a new home in a hollow tree. Then the swarm will then move to the new home.
What to do if you see a swarm?
See our Swarms page.