Most of the time, a mean hive is caused by simple genetics: A worker bee's genes determine her instinct for defensiveness* and govern how likely she is to fly up at a beekeeper or sting when she detects a threat or smells alarm pheromone.

The major difference between the two strains is that Africanized honey bees are more aggressive when their hive is disturbed. Therefore, more bees will attack anyone that disturbs them. They will also chase a person or an animal for a greater distance. It can be called a “honey bee with a bad attitude.”

Finally, a queenless colony is usually more aggressive … or, perhaps more accurately, defensive. If the queenless colony does not rear a new queen it will fail.

Having noted the affinity between bees and fruit trees, they reasoned that bees attacked and damaged fruit, and concluded that outlawing bees was the best way to preserve crops.