Africanized Honeybees or Killer Bees are well established here in Tucson, and there have been a number of attacks. Africanized Honeybees are an accidentally released hybrid between African and European subspecies of the Honeybee or Honey Bee (Apis mellifera). Africanized Honeybees thrive both in tropical and in subtropical areas. Tucson lies at the northern edge of a subtropical thorn forest, and Africanized Honeybees do quite well here. European and Africanized Honeybees look extremely similar, and away from their hives it is difficult to tell them apart.

Africanized Honeybees are far more mobile than European Honeybees, and they have adapted to follow irregular or isolated flower sources in areas with extended or year-round blooming seasons. These bees also favor night-blooming, bat-pollinated flowers like those of our Saguaro cacti which remain open for a period in the morning. European Honeybees are less mobile because they are more adapted for a temperate climate with more regular pollen and nectar sources and the need to stock up on honey for the cold winters.

The stings of Africanized Honeybees are no more dangerous than those of European Honeybees. These bees are more dangerous because Africanized Honeybees are more likely to attack and do so in greater numbers.

Unlike European Honeybees, Africanized Honeybees:

• defend their hives from farther away
• are more sensitive to disturbances around their hives
• become agitated quicker
• are more likely to respond aggressively to perceived threats
• respond to threats in much larger numbers with more stinging
• are more likely to pursue their attack victims great distances
• stay agitated longer
• swarm more frequently and establish more hives
• are more likely to abandon old hives and move to new ones
• have smaller hives and nest in smaller cavities and thus have a wider selection of nest sites in populated areas

Neither European Honeybees nor Africanized Honeybees are native to the US, and while Honeybees are absolutely essential for pollinating cultivated plants and crops, they unfortunately outcompete native bees and other pollinators at native plants.

Recently, I started having a problem with bees at a leaky hummingbird feeder in my yard. These particular bees suddenly became unusually bold and aggressive, and whenever I or my dogs went outside, these bees would come up and deliberately head-butt or bump into us, a characteristic hive-protection behavior of Africanized Honeybees.

Bumping bees don't initially sting, instead they are warning potential threats to stay away from their hives. Bumping guard bees are a clear warning of a potential bee attack, and here in Africanized Honeybee territory, it's best to leave the area if bumping bees or a visible wild beehive are ever encountered.

I couldn't find any nearby hives, so I don't know why the bees were doing this. It is really creepy to feel bees continuously bumping against you as you walk around outside, especially knowing that the chances are excellent that they are Africanized. These bees were also fond of landing on us, but they didn't sting either me or my dogs. I kept my dogs inside for the day until I could take down the hummingbird feeder at night when the bees were sleeping. After a day or so, the bumping stopped and the aggressive bees dispersed.