New World screw-worm fly larva (Cochliomyia hominivorax). These larvae, or maggots, are native to the New World tropics. They use their sharp mandibles (black) to eat away the flesh of warm- blooded animals, including humans. The adult flies lay their eggs in open wounds, and the larvae burrow their way into the tissue. This can severely damage or even kill the host. After 3-7 days, the larvae fall to the ground to pupate.