Screwworms are the larvae of certain species of flies, primarily the Cochliomyia hominivorax and Cochliomyia macellaria. These pests are known for infesting the wounds of mammals, including livestock and sometimes humans. The larvae feed on living tissue, which can lead to severe infections and even death if not treated promptly. Screwworms are a significant concern in agriculture, particularly in the United States and Latin America, where they can cause substantial economic losses in livestock. Control measures often include the use of sterile insect techniques and insecticides to manage their populations and prevent outbreaks.