The larval gut ends blind. Solid waste from digestion is stored in the hindgut region rather than excreted, an arrangement shared with some other insect larvae that live in enclosed spaces or, as here, in a clean sand pit that fouling would betray. The accumulated material, the meconium, is expelled shortly after the adult emerges.
Feeding is external. The larva's long jaws each carry a groove, closed by the maxilla into a channel, through which digestive enzymes are injected and liquefied tissue drawn back. The empty husk of the prey is flicked out of the pit.
The pit itself is built by spiralling backwards through the sand and throwing loads clear with the head. Its walls sit at the angle of repose, so an ant that steps over the rim slides, and the larva's flicked sand grains keep it sliding. Not all antlion species build pits; many simply hunt buried in loose substrate.