Once it has finished sucking the juices out of the prey, the antlion larva uses the same throwing motion of the head that it used to catch the prey to fling its now-lifeless body out of the crater.
Antlion larvae pass the winters in a dormant stage deeper in the ground (Grzimek 1979, 224) and have been known to remain as larvae for up to three years.
What happens to all the food an antlion larva consumes during its life? Do antlions "go to the bathroom"? Yes and no. Antlions excrete some fluid during their larval life. If you keep antlions as pets you might notice small "sugar lumps" in the sand; these are merely sand grains stuck together from excreted fluid (Mansell 2001). But the antlion's digestive tract lacks an external opening for solid waste, so feces accumulate within its body for the entire larval stageup to three years! Some of the waste is processed into silk for later use during the pupal stage (Arnett 1985, 249-250); the remainder is voided by the adult when it emerges from the cocoon.