housefly, common name of the fly Musca domestica, found in most parts of the world. The housefly, a scavenger, does not bite living animals but is dangerous because it carries bacteria and protozoans that cause many serious diseases, e.g., typhoid fever, cholera, and dysentery. The housefly feeds by depositing a drop of digestive liquid on its food, which may be garbage, excrement, or other filth. Although most of the liquid drop is sucked back again through the insect's tubelike lower lip, or labium, a residue remains that may contain disease-causing organisms from previous meals. Disease is also transmitted on the fly's sticky foot pads and hairy body. Each female lays from 100 to 200 eggs in the garbage or manure on which the white larvae feed. With favorable temperatures, one generation or more per month may be produced. Metamorphosis is complete, i.e., development is in four stages. The housefly is classified in the phylum Arthropoda, class Insecta, order Diptera, family Muscidae. For methods of control see bulletins of the U.S. Dept. of Agriculture.