It is important to differentiate a bee sting from an insect bite. It is also important to recognize that the venom or toxin of stinging insects is quite different. Therefore, the body's reaction to a bee sting may differ significantly from one species to another.

The most aggressive stinging insects are vespid wasps (including bald-faced hornets and other yellowjackets) but not hornets in general (e.g., the European hornet is gentle). All of these insects aggressively defend their nests, although they have not developed a sting targeted at mammals like the honey bees.

In people who are allergic to bee stings, a sting may trigger a dangerous anaphylactic reaction that is potentially deadly. Honey bee stings release pheromones that prompt other nearby bees to attack.

Honey bee stings

Although it is widely believed that a worker honey bee can sting only once, this is a partial misconception: although the sting is in fact barbed so that it lodges in the victim's skin, tearing loose from the bee's abdomen and leading to its death in minutes, this only happens if the victim is a mammal (or bird). The bee's sting evolved originally for inter-bee combat between members of different hives, and the barbs serve to improve penetration of the chitinous plates of another insect's exoskeleton. When bees sting elastic-skinned mammals, the barbs become a hazard to the bees as described above. This shows that encounters with mammals are of litle evolutionary significance in bee survival. Honey bees are the only Hymenoptera with a strongly barbed sting, though yellowjackets and some other wasps have small barbs.

The sting's injection of apitoxin into the victim is accompanied by the release of alarm pheromones, a process which is accelerated if the bee is fatally injured. Release of alarm pheromones near a hive or swarm may attract other bees to the location, where they will likewise exhibit defensive behaviors until there is no longer a threat, typically because the victim has either fled or been killed.(Note: A true swarm is not hostile - it has deserted its hive and has no comb or young to defend). These pheromones do not dissipate or wash off quickly, and if their target enters water, bees will resume their attack as soon as it leaves the water.

The larger drone bees do not have stings. In worker bees, the sting is a modified ovipositor. The queen bee has a smooth sting and can, if need be, sting skin-bearing creatures multiple times, but the queen does not leave the hive under normal conditions. Her sting is not for defense of the hive; she only uses it for dispatching rival queens, ideally before they can finish pupating. Queen breeders who handle multiple queens and have the queen odor on their hands are sometimes stung by a queen.