ミツバチ
The stinger consists of three parts: a stylus and two barbed slides (or lancets), one on either side of the stylus. The bee does not push the stinger 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 female honey bee stings a person, it cannot pull the barbed stinger back out, but rather leaves behind not only the stinger, but also part of its abdomen and digestive tract, plus muscles and nerves. This massive abdominal rupture kills the honey bee. Honey bees are the only bees to die after stinging.