Lucilia sericata, Chrysomya albiceps and Musca domestica larvae have been successfully used routinely for the clinical treatment of difficult necrotic and infected wounds. Degradation by proteinases contained in larval excretory/secretory (ES) products is thought to contribute to wound debridement by removal of dead tissue. However, proteinase activity may also affect host tissue remodeling processes (Chambers et al., 2003), for hundreds of years, the beneficial effects of maggots on wound healing have been documented. Insects have to defend themselves from infection by a wide variety of potential bacteria and fungi. In addition to some of flies have beneficial effects in medicine especially, L. sericata which used in Maggot Debridement Therapy (MDT). Maggot therapy success is partly due to the ingestion and killing of living microorganisms but antibacterial activity of excretion/secretion (ES) that included the salivary gland secretions and faecal products of L. sericata has been demonstrated in vitro.