San Diego Natural History Museum--Your Nature Connection[BRCC San Diego Natural History Museum: Entomology Department]

The Collection
Historical Highlights

Field Guide

Michael Wall, Ph.D.
fax: 619.232.0248


How Did They Get Here?

In the 1950's, Brazilian scientists brought African honey bees to crossbreed with Brazil's local European honey bees. They hoped to produce a hybrid with greater tolerances for tropical climates. Several of the African bee colonies escaped into the wild and, encountering no natural enemies, thrived and successfully crossbred with European honey bees. The Africanized hybrids spread throughout South America and Central America, moving at a rate of 250 to 350 miles per year. In the fall of 1995, the bees entered southeastern California.

Africanized Honey Bees

Identifying Africanized Honey Bees

Africanized honey bees are physically similar to European honey bees. There are few distinctive traits that can be observed with the naked eye. Definite identification must be performed in a laboratory where more than 20 different structures are measured and compared, or the DNA and enzymes are analyzed.

More apparent differences lie in the behavior of the bees.

  1. Africanized honey bees are highly defensive and easily agitated. In as little as three seconds, they will respond to a perceived threat with considerable force. European honey bees take as long as 30 seconds to react to a perceived threat.
  2. Africanized honey bee colonies have a larger proportion of soldiers among their workers than European colonies. An Africanized honey bee colony may have as many as 2000 soldiers ready to defend it; the European honey bee colony uses 1/10th that number.
  3. Africanized honey bees will pursue a perceived antagonist as far as 1/4 of a mile; European honey bees, about 30 yards.
  4. During an attack, the Africanized honey bees deliver as many as ten times the number of stings as their European counterparts.
  5. Africanized honey bees may need one or two days to calm down after a disturbance. European honey bees usually calm down within a few hours.
  6. The Africanized honey bees tend to reproduce and swarm more often than European honey bees.
  7. When resources begin to dwindle, the Africanized honey bees will completely abandon the hive, taking large amounts of honey with them. This allows the colony to move over greater distances than European honey bees.
  8. Africanized honey bee swarms will take over a European honey bee hive if the hive has been weakened or the queen has died.
  9. The Africanized honey bee colony produces more drones (males) than the European hive. The Africanized honey bee drones search out mates more vigorously and successfully than the European drones.

Avoiding Trouble

While it is true that Africanized honey bees are highly defensive insects, the threat they pose to human populations has been exaggerated. Approximately 40 people die in this country each year as a result of stinging insects. To avoid trouble with bees and wasps, here are some safety suggestions:

  • Avoid swarms or wild colonies that have established in yard clutter, trees, or walls. Swarming is a normal part of the bee reproductive cycle and most bees are not dangerous when they swarm, however Africanized honey bees are very protective of their colonies, even while swarming.
  • Do not throw rocks or other objects at a hive.
  • Watch for bees when operating gas-powered mowers, blowers, or other yard maintenance machinery. Africanized honey bees are easily disturbed by the vibration and exhaust.
  • Do not wear dark clothing or strong perfume/cologne/aftershave if you must approach any bees.
  • Keep pets away from hives, especially during hikes or walks.
  • If horseback riding, avoid brush or low-hanging branches where bees might nest.


A few simple precautions can help you bee-proof your home and property.

  1. Remove any clutter from your property. Africanized honey bees are not as particular as Europeans about their nesting sites and will use almost any type of available space, including meter boxes, tires, or downspouts, for a hive.
  2. Periodically check your home and yard for indications of hives. A steady flow of bees to and from a single location is a good indication of a hive. Call a professional pest controller to have the hive removed. Do not try to remove or destroy the hive yourself.
  3. Check your exterior wall for cracks or other openings, such as holes where pipes or wiring enter your home. Fill these with caulk or steel wool. If you find that bees are already inside your exterior walls, do not block the entrance. The bees may be forced into your home as they try to find a way out of the wall.
  4. If you have chimneys or downspouts, cover the openings with fine screens (less than 1/8th inch mesh).

Emergency Measures

If you encounter Africanized honey bees:

  • Run away as quickly as possible. Protect your head, especially your eyes and mouth.
  • Get inside a secure, enclosed structure, such as a car or building, before attempting to remove any stingers. A chemical called an "alarm pheromone" is released when bees sting. It draws more bees to the victim.
  • Do not attempt to fool the bees by hiding or "playing dead" if you are stung. The bees will continue to sting you.
  • Do not jump into water, such as a swimming pool. Africanized bees will wait for a victim to surface.
  • If you are with someone who cannot run away from the bees, cover them with a blanket, tarp, or other material. This will not prevent bees already on the victim from stinging, but it could prevent additional injury. Do not stay with the victim -- the bees will turn their attention to you. Run for help.



David K. Faulkner
The Killer Bee Handbook
Nature Connection (1996) Paperback



Africanized Honey Bee Information -- County of San Diego Department of Agriculture, Weights, and Measures

UCR research and extension on the Africanized Honey Bee -- Entomology Department, University of Riverside

Bee Alert: What is the Africanized Honey Bee -- Texas A&M University Agriculture Program

Text by David Faulkner