Why are Africanized bees so defensive?
Why are African (especially sub-Saharan Africa) bees so defensive? I suppose there are a number of reasons but a big one is that bees were not kept in Africa. But honey, beeswax and larvae were harvested, which destroyed the hive. It wasn't only mankind that harvested the honey and beeswax - there were (and are) animals that attack and destroy feral bee hives in Africa - but man was a major destroyer of feral hives. That activity put evolutionary pressure on the bees to become fierce defenders of their hives. The more docile hives were destroyed by people who harvested the honey, beeswax and larvae (for protein).
A report from Africa said that when a feral beehive is found the African hunters burn the grass and shrubs around the hive, the smoke disorienting the bees and allowing the hunters to gather the comb.
In addition to fierce defensiveness of the hive, African bees produce lots of brood and swarm more often than European bees. This is in response to the very high predation of hives. If it wasn't for the predation there would be too many hives to be supported by the available forage and the bees would not have evolved to swarm so often.
Africanized bees - and I assume European bees - will attack black items more than white items. One test for Africanized bees is to put a black glove in front of the hive and then count the number of stings in the glove. It's possible that because at least one animal predator (the Honey Badger), and the people who preyed on the hives, are black that the bees evolved to associate the color black with danger and react with fierce defensiveness. Perhaps that's why we wear white bee suits.
And just to throw a picture in, Europeans destroyed bee hives before they began keeping bees in hives. This is a picture of cave art found in a cave near Valencia, Spain in the Cave of the Spider (Cueve de la Arana) situated on the river Cazunta, painted about 8,000 years ago. The pictures are of the same cave art, the second is just a close-up.