A flesh-eating parasitic fly has spread north through Mexico to within a few hundred miles of the U.S. southern border. The New World screwworm (Cochliomyia hominivorax) lays its eggs in open wounds and in the orifices of live, warm-blooded animals—including, occasionally, humans. The maggots then devour the animal's flesh, causing devastating lesions that can quickly kill the infested host. ...read more read less