Don’t be deceived by their small size—flies create huge problems in any food environment! They easily irritate customers and can quickly result in regulatory citations. They also carry bacteria (up to 4 MILLION on its body and over 28 MILLION in its tiny stomach!) and disease organisms, and contaminate food and otherwise clean environments.


House flies are a dull gray color with four black stripes down their backs. This is the most common fly found in homes and restaurants. It is widely distributed and can transmit serious diseases such as typhoid, cholera, Salmonella, dysentery, tuberculosis and anthrax. During the day, house flies tend to rest less than five feet from the ground on walls, floors and on random items. At night, house flies will change their preference and rest above five feet for the ground on ceilings, light fixtures, dangling light cords, tall plants, etc. The house fly eats only liquid food, so they spit saliva on food to pre-digest it and then suck the food back up.


Blow/Bottle flies can be colored partly or wholly metallic blue, green, or dull brassy, sometimes black. Blow/Bottle flies can be just as bad, if not worse than House flies, about transmitting diseases. Typhoid, cholera, Salmonella, dysentery, tuberculosis, and anthrax are just a few of the diseases Blow/Bottle flies can transmit. Blow/Bottle flies live and breed in dead rotting flesh. If flesh is not available, they will feed on animal excrement, decaying vegetation or garbage. Dead mice, rodents, birds or any other small animals can cause an infestation of Blow/Bottle flies inside homes and structures. Blow/Bottle flies are always the first on the scene when an animal or human dies. A lot of times the Blow/Bottle fly larvae’s are used in forensics to determine time of death in a murder case. Nasty critters! But in some cases can be a beneficial insect.


There are no distinctive marks or striping on the thorax of a cluster fly. The name reflects this species’ habit of forming compact clusters of hibernating individuals, typically in wall voids, soffits and attics. When the days get shorter and the weather cools down in the fall, cluster flies will start migrating back to structures and homes to begin their winter hibernation. A signs of this migration can be found on the south side of a structure or home where they will cluster on siding and brick walls to stay warm. Cluster flies will enter any crack or crevice of a structure to hibernate in. On sunny winter days, cluster flies will become active and enter the inside by squeezing in and around light switch covers, outlet covers, light fixtures, exhaust fans, attic fans, etc. Once inside cluster flies are attracted to light coming in through windows.


This small fly is easily identified by its red eyes (most of the time). The fruit fly’s body is tan in the front and black on the rear. Fruit flies are drawn to ripened/fermenting fruit and vegetables. Fruit flies breed in drains, garbage disposals, trash cans, mops, rags, etc. They are mainly considered a nuisance, but can contaminate food with bacteria. Sanitation is the best defense against developing a fruit fly problem. Discarding over-ripened fruit and vegetable will also help in prevention.


Fungus gnats are usually black, brown, or yellowish and have wings that might have dark patterns on them. Adults are found on/near decaying organic matter, where they lay their eggs and the larvae mature. When these gnats are found indoors, it is almost always the result of overwatering plants. Water leaks, moisture problems, or feces in bird cages can result in a gnat problem. The elimination of breeding sources is the most important step in preventing a gnat problem.


These flies have a furry body and wings, and the color can vary from yellowish, to brownish gray to black, depending on the species. They have segmented antennae that have long hairs on them. Their wings are held rooflike over the body when at rest. Because of their small size, drain/sewage flies are able to move through ordinary screens. Drain/sewage flies are weak fliers; when indoors, they are usually found crawling on walls and other surfaces. When they do fly, it is usually just a few feet at a time. They breed in sewage, but apparently do not transmit human diseases. They can be found hovering above drains, dirty garbage cans, bird baths, clogged gutters, storm drains, moist compost, rain barrels, septic tanks, etc. In minor cases, simply cleaning the drains with very hot water will take care of the problem. In more severe cases, using a stiff brush to clean the inside of the drain will be required to eliminate the slimy film they reproduce in.