Maggots on needle. Greenbottle fly larvae, or maggots (Lucilia sericata) climbing on a needle. These maggots are applied to patient wounds. The maggots eat dead and dying flesh, but leave healthy tissue untouched. They clean the wounds more efficiently than drugs or other methods. The maggots prevent the growth of harmful bacteria in the wound by altering the acidity and releasing an antibiotic compound. Only this species of maggot is used. Photographed at Zoobiotic, Wales, UK. This is Europe's largest supplier of surgical maggots.