Maggots eat plants, animals or blood, depending upon the species. Of the maggots that eat flesh, some like it decomposed, others eat live tissue and some consume a mix of both.
Maggots are the larval stages of adult flies. This stage of the fly life cycle usually lasts less than a week, with the maggot eating constantly and growing through several life stages known as instars. In the United States, the green bowfly maggot is the only species of fly larva approved for use in medicinal therapy. When a wound isn't healing, doctors apply green bowfly maggots to eat the dead tissue in order to clean and disinfect the wound.