 The antlion larva is a ferocious @-@ looking animal with a robust , fusiform body , a very plump abdomen , and a thorax bearing three pairs of walking legs . The prothorax forms a slender mobile " neck " for the large , square , flattened head , which bears an enormous pair of sickle @-@ like jaws with several sharp , hollow projections . The jaws are formed by the maxillae and mandibles ; the mandibles each contain a deep groove over which the maxilla fits neatly , forming an enclosed canal for injecting venom to immobilise the victim , and enzymes to digest its soft parts . The larva is clad in forward @-@ pointing bristles which help it to anchor itself and exert greater traction , enabling it to subdue prey considerably larger than itself . Antlion larvae are unusual among insects in lacking an anus . All the metabolic waste generated during the larval stage is stored , some is used to spin the silk for the cocoon and the rest is eventually voided as meconium at the end of its pupal stage . 
