Flies can transmit diseases such as typhoid fever, cholera, dysentery, anthrax, gastroenteritis, conjunctivitis, and others. A single fly may carry up to 6,500,000 bacteria. Bacteria may be carried in the digestive system for as long as four weeks, and the bacteria can be transmitted to succeeding generations. While feeding on garbage, or other attractive materials, the fly covers itself with bacteria. The fly must transform its food into a liquid, and does this by regurgitating some of the liquids already swallowed, such as sewage and bacteria-laden saliva onto the food. The liquefied food is then sucked up, but part of the regurgitated liquid is left behind. The fly leaves behind part of its vomit, germs from its legs, and its feces.

The flies of common concern are house flies, flesh flies, and blowflies. All of these flies live on garbage and can transmit disease. All of these flies are about 1/4 inch long and have short, stout, hairy bodies. All species of flies have only one pair of wings, and three pairs of legs with sticky, padded feet.

House flies have a dull gray thorax with dark stripes and a dark, dull abdomen with yellow sides. Flesh flies have a dull gray thorax with three distinct dark stripes and a gray checkerboard abdomen. The thorax and abdomen of the blowfly are shiny black, metallic green or bronze, or these flies have a metallic blue abdomen with a dull thorax.

Flies go through a complete metamorphosis. After hatching from an egg, they go through a larval stage, and then a pupal stage before turning into adults. The female fly lays its eggs in moist or fermenting garbage and decaying meat within 4 to 12 days after it is fully grown. In warm weather, the larvae, or maggots, hatch out from the eggs in 10 to 24 hours, become pupae in about 4 to 10 days, and adults in 3 to 6 days. Houseflies and similar flies normally overwinter as adults in structures or other sheltered places.

The diseases transmitted by flies can best be controlled by controlling the fly population, and by eliminating sewage nuisances. Controlling the fly population is best achieved by making food inaccessible, and eliminating breeding sites. The application of good sanitary practices, especially in regard to the proper handling and disposal of garbage, is an important means of restricting the food supply of flies. Garbage should not be left exposed for a longer time than necessary to deposit the garbage in proper waste containers. Garbage should be placed in proper waste containers with lids that can be sealed tight, and garbage should be disposed of properly at least once a week.

Clermont County Public Health regulates the handling and disposal of garbage under Public Health Nuisance Regulation 2-93, Section 6, and sewage under Section 5. Public Health also regulates the disposal of animal carcasses when such disposal is in violation of Section 6, or of the Solid and Infectious Waste rules. Public Health does not regulate the disposal of animals that have been killed as the result of road accidents.