Why do bees swarm?

[GaryMinckler]

Is it simply a matter of crowding in the hive?

[Bcrazy]

Hi GaryMinckler
I'm from across the pond but beekeeping is very similar wherever it occurs.

Is it simply a matter of crowding in the hive?

The simple answer is No.
There are many factors affecting the colony before it swarms.
Season; it has been shown that swarming can occur in heavy numbers in a certain year and very slight another year.
Weather; weather patterns are associated with when bees swarm.
State of the flow; this is said to affect the propensity to swarm.
Ventilation; which is a contributory factor.
Comb space; this is directly related to congestion and is a contributory factor.

If the colony are not getting enough queen pheromone then they will build queen cells.

The start of swarming in a colony certain 'things' happen.
House bees will be reluctant to accept nectar loads from foragers.  Foraging diminishes and redundant foragers will look for new nesting sites. The queen is not feed which will allow her to slim down so she can fly and because of this egg laying almost stops.
So how as a 'beek' do you realise the colony is preparing to swarm?
Check for eggs in play cups or the beginnings of queen cells. If there are no eggs then don't worry about swarming. If there are eggs and the eggs have moved on to the larva stage and been fed royal jelly then that is a positive sign they are preparing to swarm.
How you counter that is up to yourself as there are many methods of swarm control.
Hope that has shed a bit of light on the subject of swarms.

Regards;

[Scadsobees]

Not to mention genetics....some bees are more prone to swarm, perhaps because of how they build up and use stores.

[sc-bee]

To reproduce and multiply!!! Everything we do just gets in the way of their objective ;)!

[GaryMinckler]

Thanks all.  Just had a swarm and had no idea why...I think there was lots of room left.  Very interesting stuff.  Thanks again!!

[JP]

To reproduce and multiply!!! Everything we do just gets in the way of their objective ;)!

My swarming season starts the beginning of March. Those swarms are mostly reproductive ones, its an inate urge for propagation.

They will also swarm or abscond from a fallen tree once the combs are disoriented and laying atop each other.


...JP

[Ross]

Same reason any animal reproduces, because it can.