Did you know that all honey bees come from the Old World? Before Europeans discovered the Americas, both continents had no honey bees.

First, European colonists brought the honey bee we’re most familiar with (the European honey bee) to the Americas in the 1600s and 1700s. Then in the 1950s, beekeepers brought African honey bees to Brazil-the bees that became known as killer bees. The beekeepers hoped that the hardier variety of bee would better adapt to the tropical climate in South America.

But the honey bees went wild and invaded Brazilian rain forests by 1957. They spread throughout South America and reached the United States in October of 1990. On the journey, the bees bred with the more mild-mannered European honey bees to produce a new variety of bee: Africanized honey bees.

The Africanized honey bees are more aggressive, defensive, and persistent than European honey bees. That makes them more difficult for professional beekeepers to work with, and it also makes them more dangerous around ordinary people.

Let’s go over the physical and behavioral differences between Africanized and European honey bees.

European Honey Bees

European honey bees have more calm demeanors than their Africanized brothers. Although you still want to avoid disturbing a hive, European bees tend to cause less damage and exhibit less aggression.

• Fill or cover all holes 1/8-inch in diameter or larger in trees, structures and block walls.
• Caulk cracks in wall, in foundation and in the roof.
• Check where the chimney meets the house for separation and make sure chimneys are covered properly.
• Put window screen over drains, attic vents, and irrigation valve boxes.
• Remove any trash or debris that might serve as a shelter for bees, such as overturned clay pots, automobile parts, tires, old appliances, cardboard boxes, or stacks of crates.
• Fill or cover animal burrows in the ground.
• Make sure window and sun screens are tight fitting.
• Keep shed doors tightly closed and in good repair and exercise caution when entering buildings that are not used frequently

Africanized Honey Bees

To contrast, Africanized honey bees are far more defensive of their nests. They breed faster, are harder to find, and are more aggressive than the mild European honey bee.

• The bees can send out several hundred guard bees in response to disturbances up to 40 yards away.
• Once they’re agitated, the bees remain defensive for days instead of hours.
• A disturbed Africanized colony may sting a disturber 6-10 times more than a disturbed European colony.
• The bees swarm 10 or more times each year.
• The swarms are much smaller. Sometimes they’re as small as a softball or a coffee cup. That means their nests take up less volume.
• Most of the time they only need a cavity of 1-5 gallons to nest.
• The bees often abandon their nests and move to a better nesting location.
• The bees choose underground cavities to nest. They also don’t need the space to be dry or clean-they often choose moist, dirty locations.
• They choose unprotected, exposed locations for their nests.
• The bees require only a small group to start a new colony, so the nests are difficult to find until they are disturbed

Is There Any Way to Tell the Bees Apart?

Physically, Africanized honey bees look just like European honey bees. Usually you have no way to tell the two breeds apart without viewing their behavior. Unfortunately, the only way to observe their behavior involves causing aggression, which is not advisable. If you find any bees on your property or in the wild, call a professional exterminator to identify and solve the problem.

Why Are Africanized Bees Taking Over?

Unfortunately, because Africanized honey bees are so aggressive, they often drive the more mild European honey bees from the habitat humans have created for them. Not only that, but they have faster growth rates, they can produce more nests, and they produce more drones per colony than European honey bees do. Since they often relocate their nests, they also take over European honey bee nests and replace European queens with Africanized queens.

But the most important reason that Africanized honey bees are driving out the European honey bees is that the European honey bees tend to mate with the Africanized variety in higher numbers. Africanized honey bees produce more drones per colony, which means that they produce more potential mates for the queens than European colonies do. On top of that, European honey bee queens prefer to mate with Africanized drones over European drones.

Whenever an Africanized bee mates with a European bee, they tend to produce more Africanized bees. The African honey bee genetic traits are more dominant than the European honey bee traits. Since the Africanized bees are more powerful, aggressive, and attractive than their European counterparts, they’ve taken over the American Southwest.

What Can You Do?

If you find a swarm of bees or a nest, don’t hesitate to call a professional. A qualified exterminator will be able to tell you if you have a nest of European honey bees or Africanized “killer” bees. Then they’ll take care of the problem for you.