Every now and then, you hear about a bee swarm and wonder what makes them do it.

Disruptive Bee Swarms

In Little Rock, Arkansas, one spring, a swarm of bees estimated to be about 7,000 strong forced a hospital emergency room to shut down. A beekeeper was called to vacuum up the bees and take them away. The ER was closed to protect patients and visitors who might be allergic to bee stings, whether they know it or not.

In Redondo Beach, California, the Fire Department reported that it receives and responds to about 18 calls per month about bee swarms. The Fire Department will treat multiple bee sting injuries or people who are allergic to bee stings and have been stung, but they will not remove hives from private property. They advised residents to bee-proof their homes as a preventive measure by removing items bees can use for hives, like old tires, boxes, containers, and wood piles. Residents should never attack a bee swarm with a can of bug spray, as this will stir up the bees and make the situation even worse.

Why They Swarm

Beekeeper Harvey Johnston, who removed the beehive from the Little Rock hospital emergency room, says bees swarm because the hive gets overcrowded. The queen leaves the crowded hive, and a portion of the bees leave with her, all at once.

The Redondo Beach Fire Department, however, reports that bees also swarm to protect the location of their hives. The African bee, which is more aggressive than the European honey bee, is much more likely to swarm as a hive protecting measure, especially when the honeycomb is at its most productive.

Unfortunately, these bees respond to vibrations in the air up to 200 feet away from the hive, so they can be attracted by the sound waves from a lawnmower or chainsaw, or even an outdoor stereo system playing music at high volume.

What to Do When Bees Swarm

If you find yourself in the midst of a bee swarm, move calmly to the nearest indoor shelter. Take any pets indoors with you, as just a few bee stings can kill your beloved dog or cat. If you are outdoors without shelter but there is a river or lake nearby, get into the water, and take your pets with you.

Remember, most bees mean you no harm. Bees pollinate more than one-third of the food crops we need to survive as humans, and even more crops that feed non-human animals. They also produce honey and wax. Bees are not pests; they are valuable members of society.