 The eggs hatch out within the feces producing first stage larvae.After the eggs have hatched in the feces, the larvae are ingested by the maggots of various flies that lay their eggs in the feces (such as "Stomoxys" (the stable fly) or "Musca" (the house fly).The nematode larvae develop within the maggot for about one week (depending upon ambient temperature), as the maggots mature into the imago (adult) fly.