Pest Problems After Storms – Flies in Homes

Food in a refrigerator that had lost power

Refrigerator with rotting food

When electrical service is lost for an extended period, unprotected perishable foods begin to spoil. Flooding inside homes can complicate this problem. House flies, fruit flies, “scuttle flies” and blow flies will be attracted to these decaying items. Perishable foods that are no longer usable should be placed in trash bags and discarded in a trash can until trash is picked up, or else taken to a sanitary landfill or other municipal disposal site. Make sure that garbage can lids fits tightly. Fly traps and baits are often effective but with an abundance of other food sources (such as decayed food in dumpsters and non-working refrigerators and freezers), they will not attract the flies away from the sources.

Food (or disposable food dinnerware and trash) that is carelessly discarded or placed in a lidless (or poorly-fitting) garbage cans or simply in bags stacked on the ground will attract displaced hungry wildlife, such as raccoons, skunks, stray dogs and small rodents.

For additional information about post-storm food safety and cleaning of kitchens and appliances, visit the website:

Water-logged carpet piled in front of a house.

Water-logged carpet piled in front of a house.

Water-soaked lawns, compost piles, discarded carpeting, padded furniture, insulation and clothing become moldy and serve as breeding grounds for fungus gnats and other flies. Water-soaked compost piles, grass clippings or bales of hay and straw may attract stable flies. Depending on the time of year, the adults may show up in about 7-10 days and become a nuisance. Particularly when electrical service is disrupted or when homes are flooded, people leave their windows and doors open to improve air circulation. Unscreened windows and doors (or ones with damaged or poorly-fitting screens) provide flies with easy access to homes. Aerosol insecticides may control flies temporarily, but more flies will appear once the chemical has dissipated. Pesticides must be used carefully and should not be applied around children and people who have respiratory problems that may be complicated with other problems (such as mold during cleanup). Use sticky “fly strips” to trap the flies. “Pest strips” impregnated with the chemical DDVP (dichlorvos) should not be used except in rooms that are NOT occupied more than four hours daily or where they are accessible to children or pets.

Septic systems damaged by uprooted trees  will attract a variety of small flies, including “humpbacked flies”, minute scavenger flies and moth flies. These flies will increase noticeably around damaged septic lines, damaged sewer pipes (both under houses or along roads) and other waste system components. Moth flies showing up outdoors or inside may be a sign that you need to check your septic system and crawl space for possible damage to septic lines or waste pipes.

Carcasses of animals killed in a storm or in subsequent flooding will attract blow flies in particular. Quick disposal of the carcass is critical to minimizing fly problems; however, post-storm conditions may disrupt cleanup activities and delay disposal. Listen for instructions from county or state health officials regarding what methods are considered appropriate in your area. For small animals (domestic or wild), incineration or disposal in an appropriate landfill are preferable. In some emergency situations, local officials may approve immediate burial at least 3 feet deep, but check with your local government before burying dead animals even on private property. Do not place carcasses in dumpsters unless you are instructed to do so as this will only aggravate fly problems particularly if the dumpsters cannot be emptied quickly and regularly.

Additional problems can arise in and around livestock and horse farms. These problems can impact on both farmers and surrounding neighbors as well.

Written By

Photo of Dr. Michael WaldvogelDr. Michael WaldvogelExtension Specialist (Household & Structural Entomology) (919) 515-8881 mike_waldvogel@ncsu.eduEntomology and Plant Pathology - NC State University
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