When an existing colony prepares to swarm, the bees produce anew queen. Then the old queen and about half of the worker bees will leave the parent colony to establish a new colony. It is this group of bees we call a swarm. Although a swarm appears quite dangerous, honey bees are usually extremely gentle when swarming. A swarm does not contain stored food or young bees, so the bees have nothing to defend and are unlikely to sting.
Honey bees are most likely to sting when an established colony is disturbed.
When a swarm selects a nesting site, the bees begin building comb in which to store food and rear young. Within 2 to 4 weeks, this colony of bees will have developed the defensive nature that the swarm lacks. If an established colony of bees is disturbed, the bees will respond by attacking anything within their territory. This is true for both Africanized and European bees. However, Africanized bees respond more rapidly and intensely than European bees and usually sting in larger numbers.