A worker's jobs

A worker does not do one job for her whole life: she moves through a sequence timed to her own age.

• In her first two or three days, she cleans cells and caps brood.
• From about day three to day twelve, she nurses, feeding larvae with glands that peak in that window.
• Through her early teens, she shifts to middle-aged hive work: building comb, processing incoming nectar, tending the queen, hauling out the dead.
• Around day eighteen, she takes up guard duty at the entrance, checking every bee that lands.
• From about day twenty onward, until she wears out, she forages, and foraging is what finally kills her.

This sequence is not fixed law: a colony that loses its foragers pushes young bees into flight early, and one that loses its nurses pulls foragers back to the brood nest.