Louisiana is home to a great number of fly species that are considered pests, including stable flies, horse flies, deer flies, fruit flies, phorid flies, blowflies, and cluster flies. Each of these fly groups are comprised of anywhere between several to hundreds of species, and the first three groups listed are generally outdoor fly pests, while the remaining four fly groups are well known for being both indoor and outdoor pests. Musca domestica, or the common housefly, is the most frequently encountered fly pest species in homes throughout the US where they pose a significant nuisance to residents. While house flies may seem like nothing more than an occasional annoyance within homes, they are actually capable of carrying more than 100 pathogenic microorganisms that are known for causing human disease.

Common house flies, like many fly pests, are in the habit of crawling about on excrement, rotting food, garbage and other sources of decaying organic matter where they acquire a variety of pathogens that the pests transport to indoor surfaces and food sources. These pathogens cause a variety of illnesses, including diarrhea, dysentery, typhoid, cholera, poliomyelitis, intestinal worms, eye infections, yaws, anthrax, and tularemia. Luckily, humans do not often fall ill as a result of making contact with pathogens spread by flies, but public health professionals agree that house flies are just as dangerous as cockroaches when it comes to their potential for spreading diseases within homes, buildings and other human dwellings. In fact, it is now believed that house flies are more apt than cockroaches to spread Salmonella and Shigella to humans within indoor environments, as flies make contact with food sources more frequently than cockroaches. It is difficult to account for the number of cases in which flies spread disease to humans, but experts have noted that outbreaks of diseases that cause diarrhea become most common during the time of year when house flies are most abundant around humans. Sealing entry points on the exterior walls of houses, like foundation cracks, and making sure windows are properly screened can go a long way at preventing indoor house fly pest issues. If the source of a house fly infestation cannot be determined, then the flies may be congregating on decaying food sources that have collected in obscured indoor areas, such as behind appliances.

Have you ever experienced a serious indoor house fly infestation?