Do doctors ever use bugs for medical reasons?

Leeches and blow fly maggots are both utilized in medicine on occasion. The Food and Drug Administration of the United States considers both bugs to be "approved medical devices", making them the first living creatures to be so labeled. Blow fly maggots devour dead tissue, which aids in the killing of pathogens, the cleaning of open wounds, and the stimulation of healing. Leeches extract excess blood from the body, and their saliva includes a potent blood thinner. Every week, thousands of laboratory-grown maggots are transported to hospitals across the United States.

Insects also provide a diverse range of chemicals with antibacterial and anti-tumor properties, as well as insecticides. They also provide a low-cost high-breeding model organism for evaluating and testing novel chemicals, whether synthetic or natural in nature. Because of their negatively charged cell membranes and ability to induce apoptosis and necrosis, compounds known as defensins, which are not harmful to healthy mammalian cells, may be beneficial in malignancies. Non-peptide chemicals such as cantharidin have the potential to have numerous anti-tumor actions.