The Africanized bee (Apis mellifera scutellata), or "killer bee," is an extremely aggressive honeybee. This bee developed when African honeybees were brought to Brazil to mate with other bees to increase honey production. The imported bees were accidentally released and they have since spread northward, traveling at a rate of 300 mi (483 km) per year. The bees first appeared in the United States at the Texas-Mexico border in late 1990.

The bees get their "killer" title because of their vigorous defense of colonies or hives when disturbed. Aside from temperament, they are much like their counterparts now in the United States, which are European in lineage. Africanized bees are slightly smaller than their more passive cousins.

Honeybees are social insects and live and work together in colonies. When bees fly from plant to plant, they help pollinate flowers and crops. Africanized bees, however, seem to be more interested...