Active and enterprising, they know how to escape the venomous fangs of their redoubtable adversaries, which they chase and paralyze before carrying them to their place of nesting. This having been done, they drag their victim in, lay an egg on its side, then close the hole and depart forever. The egg produces a larva which sucks the juices of its victim, devours it, and leaves only its appendages untouched. It encloses itself immediately in a cocoon and transforms there to a nymph. When its evolution is finished, the adult pompilid throws off its nymphal skin, opens the cocoon, and leaves the nest.
Such is, in brief, the history of the pompilids. Some of them do not hunt, and simply lay their egg upon victims paralyzed by other individuals. After the custom of the cuckoo, they make their offspring benefit by the food which an unfortunate congener has collected for its own. These are, in fact, veritable parasites.