Why do bees die when they sting you?

Only honeybees die, and only when they sting a mammal. The cause is the structure of the sting itself.

The barbed sting. A honeybee's sting has backward-facing barbs along the shaft, like a harpoon. Driven into elastic mammalian skin, the barbs catch and hold. When the bee tries to withdraw or is brushed away, the sting stays embedded — and because it is anchored, it tears free along with the venom sac, muscles and part of the bee's abdomen.

The injury is fatal, and the bee dies within minutes.

The sting keeps working after detachment, which is the useful part from the colony's perspective. Muscles attached to the venom sac continue contracting and pumping venom for up to a minute, so the bee delivers a full dose even after death. This is also why the removal advice matters — get it out quickly by any means. The traditional instruction to scrape rather than pinch is widely repeated, but research indicates speed matters far more than technique, since venom continues entering while you fuss about method.

Why evolution permits it. A honeybee worker is sterile and does not reproduce. Her genetic interest lies entirely in the colony's survival, so a defensive act that kills her but protects tens of thousands of relatives is favoured by selection. This is a standard example of kin selection.

The barbs are specific to mammals. Against another insect — the more common threat, since colonies are raided by wasps and other bees — the sting penetrates a hard exoskeleton and withdraws cleanly. A honeybee can sting an insect repeatedly without harm. The barbs are effectively an adaptation against vertebrate raiders that costs the individual her life.

Which bees do not die: bumblebees and solitary bees have smooth stings and can sting repeatedly. So can wasps and hornets, which is why a disturbed wasp is more dangerous.

Male bees have no sting at all.