Collective forces of black soldier fly larvae

Black soldier fly larvae are edible maggots that transform tons of food waste into sustainable protein per day. Although they are known to have a collective motion around and inside food sources, a physical understanding of their high eating rates is missing. We show that quorum sensing, not chemotaxis, is responsible for larvae finding food, and investigate a zone of high activity of larvae that forms near food. Using constant strain compression experiments, we demonstrate that these larvae exert an active pressure in addition to the elastic pressure of their bodies. We treat larvae as an active matter system and model their pressure with a mechanical theory. Larvae pressure increases when the larvae become more active, for example when they are consuming food. The high activity of larvae near food increases their interactions with each other, which helps larvae find food even though they are unable to smell it.