Pasadena Public Health Department

Africanized Honey Bees


Africanized honey bees (AHB), also called “killer bees”, became established in Texas in 1990 and are spreading to other southern states. AHB are expected to enter southern California by the mid 1990’s and eventually migrate throughout the state. Although its “killer” reputation has been greatly exaggerated, the presence of AHB will increase the chances of people being stung.

Learning about the AHB and taking certain precautions can lower the risk of being injured by this new insect in our environment.

The Africanized honey bee is closely related to the European honey bee used in agriculture for crop pollination and honey production. The two types of bees look the same, and their behavior is similar in many respects. Neither is likely to sing when gathering nectar and pollen from flowers but both will sting in defense if provoked.

A swarm of bees in flight or briefly at rest seldom bothers people; however all bees become defensive when they settle begin producing wax comb and when raising their young.

Africanized and European Honey Bees

  • Look the same
  • Protect their nest and sting in defense
  • Can sting only once
  • Have the same venom
  • Pollinate flowers
  • Produce honey and wax

Africanized honey bees are less predictable and more defensive than European honey bees. They are more likely to defend a greater area around their nest. They respond faster and in greater numbers although each bee can sting only once.

Africanized Honey Bees…

  • Respond quickly and sting in large numbers
  • Can sense a threat from people or animals 50 feet or more from the nest
  • Sense vibrations from power equipment 100 feet or more from nest
  • Will pursue an enemy ¼ mile or more
  • Swarm frequently to establish new nests
  • Nest in small cavities and sheltered areas

Where do AHB nest?

  • Empty boxes, cans buckets or other containers
  • Old tries
  • Infrequently used vehicles
  • Lumber piles
  • Holes and cavities in fences trees or the ground
  • Sheds garages and other outbuildings
  • Low decks or spaces under buildings

Note: Remove potential nest sites around buildings. Be careful wherever bees are present.

General Precautions

  • Listen for buzzing indicating a nest or swarm of bees
  • Use care when entering sheds or outbuildings where bees may nest
  • Examine work area before using lawn mowers, weed cutters and other power equipment
  • Examine areas before tying up or penning pets or livestock
  • Be alert when participating in all outdoor sports and activities
  • Don’t disturb a nest or swarm—contact a pest control company or an emergency response organization
  • Teach children to be cautions and respectful of all bees
  • Check with a doctor about bee sting kits and procedures if sensitive to bee stings
  • Develop a safety plan for your home and yard
  • Organize a meeting to inform neighbors about the AHB to help increase neighborhood safety

Bee-Proofing Your Home

  • Remove possible nesting sites around home and yard
  • Inspect outside walls and eaves of home and outbuildings
  • Seal openings large than1/8” in walls around chimneys and plumbing
  • Install fine screens (1/8” hardware cloth) over tops of rain spouts, vents and openings in water meter/utility boxes
  • From spring to fall, check once or twice a week for bees entering or leaving the same area of your home or yard

As a general rule, stay away from all honey bees swarms and colonies. If bees are encountered, get away quickly. While running away, try to protect face and eyes as much as possible. Take shelter in a car or building. Water or thick brush does not offer enough protection. Do not stand and swat at bees; rapid motions will cause them to sting.

What to do if stung

  • Go quickly to a safe area
  • Remove stinger as soon as possible
  • Don’t’ squeeze stinger; pressure will release more venom
  • Scrape stinger out with fingernail knife blade or credit card
  • Wash sting area with soap and water like any other wound
  • Apply ice pack for a few minutes to relieve pain and swelling
  • Seek medical attention if breathing is troubled if stung numerous times or if allergic to bee stings

For more information

  • Call 911 for multiple stinging emergencies or to report a bee problem during after-hour and weekends if there is a bee hive or swarm on city properties such as parks, city trees, streets, and sidewalks   
  • During normal business hours, call the following for behive complaints:
    • Parks, in medians or other landscaped areas - Department of Public Works Parks and Forestry (626) 744-4321
    • City buildings - Department of Public Works Building Systems (626) 744-3810
    • Water Meter - Department of Water & Power (626) 744-7617
    • Electric Wooden Power Poles - Department of Water & Power (626) 744-6982
    • Water Wells/Reservoirs - Department of Water & Power (626) 744-3890  
  • Call a licensed pest control company for honey bee swarms or hives found on private properties. Licensed pest control companies are listed in the yellow pages of the phone book.
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