Close up of flesh fly Sarcophaga bullata using its sponge_like mouthpart to lap up juices from decaying meat. The mouthparts are lined with bristles that are sensitive to taste. Flesh flies are medium sized flies with large red multi_faceted eyes that feed on the flesh of dead animals, dung and decaying material. Some species are known to deposit their larvae in the open wounds of living mammals, a behavior that gives them their common name. As with most flies, flesh flies are responsible for the spread of a variety of infectious diseases.