Ants of the genus Myrmecocystus use specialised workers, called repletes, as living food stores. Their abdomens are inflated to a huge size with a pressurised gas bubble that is gradually displaced by a sugary liquid. To avoid wasting energy, the repletes barely move and spend the rest of their lives clinging to the ceiling of the nest in clusters. When a worker needs food, it strokes a replete with its antennae and it regurgitates a mouthful. If they fall from the ceiling, they can’t climb back up and instead are dismembered by the workers. The balloon of food remains on the nest floor for a week or more as the workers gradually transfer its contents to other repletes. A single colony can have 1,500 repletes that hold up to a kilogram (2.2 pounds) of stored food between them.