What is a honey bee swarm?
The term "swarm" is not used to refer to attacking bees. In fact it's quite the opposite and honey bee swarms are usually quite docile keeping to themselves and generally will not bother you if you give them 10-15 feet of space. Swarms are usually temporary and will last from hours to days while they try to find a new home.
Why does a hive swarm?
The bees in a hive can be thought of as a collective organism and not individual bees. When conditions are ideal like anything else in nature they will try to reproduce by splitting into a new hive. The queen leaves the hive to find a new home and will take up to half of the bees with her leaving a new queen to take over the old hive.
What does a swarm look like?
A cluster of bees holding onto each other all huddled together. There will be a few scout bees flying that are looking for a new home and the rest will stay close to the queen waiting.
When do swarms occur?
They typically occur when food resources (pollen and nectar) are in abundance and the hive is strong in numbers. Usually this is anytime between April and August with the peak around May/June.
Why not leave a swarm to find a new home?
If you live in a rural area with lots of hollow trees that could probably work. However in populated areas this is problematic since the most likely places to find hollow cavities will be in someone's walls, attic or chimney. Once they establish themselves in someones house they are difficult to remove and will often require cutting into walls/siding which is costly and a traumatic process that does not have good odds for their survival.
What should you do if you find a swarm?
Call a beekeeper. Most beekeeper clubs have a swarm list of people that will come and get swarms typically for free. If that fails you can also try a non-emergency number for the police/fire department to see if they have references for beekeepers.
If you find a swarm in the Seattle area you can give me a call (206-354-977four) and if possible I will pick them up for free. If you are elsewhere in WA state you can refer to the Washington State Beekeepers Association swarm list (http://wasba.org/local-beekeeping-organizations/swarm-control) to find someone to help from your area.
Honey bees populations world-wide are in decline so please do not to spray or poison a honey bee swarm.
Also checkout my write-up published in the Queen Anne View