A honey bee away from the hive foraging for nectar/pollen will rarely sting, except when stepped on or roughly handled. Honey bees will actively seek out and sting when they perceive the hive to be threatened. Although it is widely believed that a worker honey bee can sting only once, this is a partial misconception: although the stinger 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 skin of the victim is sufficiently thick, such as a mammal's.
The sting consists of three parts: a stylus and two barbed slides, one on either side of the stylus. The bee does not push the sting in but it is drawn in by the barbed slides. The slides move alternately up and down the stylus so when the barb of one slide has caught and retracts it pulls the stylus and the other barbed slide into the wound. When the other barb has caught it also retracts up the stylus pulling the sting further in. This process is repeated until the sting is fully in and even continues after the sting and its mechanism is detached from the bee's abdomen.
When a honey bee stings a person, it cannot pull the barbed stinger back out. It leaves behind not only the stinger, but also part of its abdomen and digestive tract, plus muscles and nerves. This massive abdominal rupture is what kills the honey bee. Honey bees are the only species of bees to die after stinging.
|A close-up of what the stinging apparatus looks like in the skin. Photo by Kathy Keatley Garvey - LINK|
|Stinger and glands in its new owner - LINK|
|A bee sting therapist holds a bee to sting the arm of a patient at a bee farm in Silang, Phillipines. Photo credit: Eric De Castro/REUTERS - LINK|
|A patient is stung by an agitated bee being squeezed by a sting therapist at a bee hive farm in Silang, Philippines. Photo credit: Eric De Castro - LINK|
|A honey bee defending her hive, tries to fly away after stinging. Photo credit: Photo by Kathy Keatley Garvey - LINK|
|A bee sting therapist holds a bee to sting the foot of a hypertensive patient at a bee farm in Silang, Phillipines. Photo credit: Eric De Castro/REUTERS - LINK|
Info from here