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What are Killer Bees?

R. Kayne
R. Kayne

Killer bees earned their name by the characteristics of easily agitating and aggressively swarming, killing a victim by overpowering them with sheer numbers and hundreds of stings.

Unlike the common honey bee, it is not unusual for something as simple as a vibration, noise, or even the smell of fresh cut lawn to set off a swarm of killer bees. Once agitated, killer bees can chase a fleeing victim for up to a quarter of a mile (half a kilometer). If the victim jumps into a body of water, the bees will swarm over the surface, waiting for the victim to come up for air. Killer bees have killed both animals and people.

A honey bee.
A honey bee.

Killer bees look virtually identical to the common honey bee, which is not native to the United States but was imported from Europe by settlers for honey. European honey bees are comparatively docile, more discriminating than killer bees about where they choose to nest, and produce more honey.

In 1956 Brazilian scientist Warwick Estevam Kerr was tasked with discovering why the European honey bees in South America were not producing adequately. Suspecting the warm climate might be the problem, he crossbred bees from tropical Africa, known for being aggressive, with European honey bees. The new strain, known as Africanized bees, escaped quarantine before a selection process could be completed that would have curbed the aggressive nature of the new strain. Killer bees were born and in the wild.

Killer bees have been known to attack cattle and other livestock.
Killer bees have been known to attack cattle and other livestock.

The new bees colonized at a remarkable rate of about 300 miles per year, spreading throughout the tropics of South and Central America. The first recorded migration of killer bees to arrive in the United States was in Hidalgo, Texas in October 1990. For the next 5 years they continued their colonizing trek throughout southern portions of the United States.

Experts are split on the issue of how far north killer bees will colonize. Some believe their migration will hit a natural climactic boundary along the 34th parallel. Others believe they could eventually colonize all the way north into Canada.

Killer bees are a crossbreed of bees from tropical Africa and European honey bees.
Killer bees are a crossbreed of bees from tropical Africa and European honey bees.

The sting from a killer bee produces the same venom as a common honey bee. The difference is that killer bees are more likely to attack in higher numbers and with less provocation. The first recorded human attack in the United States was in Brownsville, Texas in May 1991. The first human fatality in the United States was in Harlingen Texas, in July 1993.

If you suspect killer bees have taken up residence nearby it is recommended that you bring pets inside and contact a professional service to remove the bees. Killer bees will attack cattle, horses and other livestock as well. As a precautionary measure, seal any external places in the home where bees might find entry and nest, such as roof vents.

If attacked by killer bees experts recommend running back the way you came, and covering your head and face which are the most aggressively attacked body parts. Find shelter in a building or car. A bee can only sting once, then it dies, but stingers left in the skin contain sacs that continue to pump venom for several minutes, so remove stingers promptly and seek medical attention. Dark clothes and dark hair are known to attract bees more than light colors.

Frequently Asked Questions

What exactly are killer bees?

Killer bees, more accurately known as Africanized honey bees, are a hybrid species created by crossbreeding the African honey bee with various European honey bees. They are known for their defensive nature and tendency to swarm aggressively in defense of their hive, which has earned them their ominous nickname. Despite this, they are just as important for pollination as other bee species.

How did killer bees come to be?

Killer bees were the result of an experiment gone awry in the 1950s when a Brazilian scientist, Warwick E. Kerr, aimed to create a bee that would produce more honey and be better suited to tropical climates. He crossbred African honey bees with European bees, but some of the Africanized bees escaped, proliferated, and spread across the Americas.

Are killer bees more dangerous than regular bees?

While Africanized honey bees are more aggressive and have a lower threshold for disturbance than European honey bees, their venom is no more potent. The danger lies in their propensity to attack in larger numbers and to pursue perceived threats over longer distances, which can result in more stings than a typical bee encounter.

What should I do if I encounter killer bees?

If you encounter killer bees, the best course of action is to run away quickly and seek shelter indoors or in a vehicle. Do not swat at the bees or jump into water; they may wait for you to emerge. Cover your head and face to protect these sensitive areas as you retreat from the area.

How can we differentiate killer bees from other honey bees?

Differentiating killer bees from other honey bees is difficult through appearance alone, as they are very similar. However, Africanized bees are slightly smaller and more aggressive. Professional beekeepers or entomologists can conduct specific measurements and behavioral assessments to identify them, often relying on wing measurements and DNA analysis to confirm their identity.

What is being done to manage the spread of killer bees?

Efforts to manage the spread of killer bees include public education on how to handle encounters and avoid provoking swarms, as well as the development of strategies by beekeepers to reduce the risks. These strategies include requeening with gentler European bees and using barriers or repellents to prevent Africanized bees from taking over hives.

Discussion Comments


I have searched for some of the questions your answer here. I am a photographer and I have some great macro insect pictures. I would like to write some children's books. Can I get resource materials for some of the information you provide?


we recently had a swarm of bees on our outdoor patio, and an exterminator traced it to a BBQ grill. After he sprayed it, 1000's of bees swarmed out, and in a few minutes he scooped out several large handfuls of them. Two days later, he came back and found some more hanging around, and sprayed them, too. After two more days, when no more bees were present, I washed out the grill, and 1000's or more dead bees washed out. The exterminator said that the bees colonized in a matter of minutes, as we had been on the patio one day before, and none were present. It was an extremely episode. Welshes, Surprise, AZ

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    • A honey bee.
      By: artist_as
      A honey bee.
    • Killer bees have been known to attack cattle and other livestock.
      By: Tim Aßmann
      Killer bees have been known to attack cattle and other livestock.
    • Killer bees are a crossbreed of bees from tropical Africa and European honey bees.
      By: Ruslan Olinchuk
      Killer bees are a crossbreed of bees from tropical Africa and European honey bees.