Why a Detached Honey Bee Stinger Keeps Pumping

The sting outlives the bee. Honey bee stingers keep pumping venom into a victim even after the bee has flown away, and scientists have now determined how: a double-piston, pump-like mechanism, according to a paper published in the Proceedings of the National Academy of Sciences. The detached stinger continues to penetrate tissue and pump venom on its own — a rare phenomenon known as autotomy, per the researchers' description of it as rare. That is the odd part of the arrangement: the delivery system keeps running after its owner has left, so the venom dose is not fixed at the moment of the sting. Note the careful wording, too: pump-like, not a pump. What keeps moving is the bee's own anatomy.