In the field, larvae of Euroleon nostras build their pits in sandy areas sheltered from rain and wind. To find an appropriate place, the ant-lion moves backward in apparently haphazard directions just underneath the soil surface. Pit construction is carried out by digging in deepening and narrowing circles following an inward and downward spiral. The central cone of sand is gradually undermined and flicked out of the pit. Finally, the pit wall is covered with fine sand and the ant-lion lies buried under the substratum at the vertex of the pit. When an insect falls into the trap, it starts to scramble up the sides. The ant-lion tosses sand with its head, thus making parts of the wall slide and carry the prey into the centre. Then the prey is captured and the ant-lion tries to insert its mandibles. If the insect offers resistance, the larva frequently flicks it back and forth against the sides of the pit to disorientate it.