Blow Flies Infestation

How to Identify Blow Fly Infestation

If you notice blow flies in your house all of a sudden, and they’re hard to miss because of the loud buzzing sounds they make, chances are, there may be a dead animal nearby. If you have a dead animal under your house or in your home, you will most likely be alerted by the smell of rotting flesh as well. Slightly larger than true houseflies, blow flies are metallic green, blue-orange or black in color. They are adult forms of maggots that might be infesting a dead bird or small animal in your yard or rotting meat in your garbage can or compost pile.

How can Blow Flies Affect Humans?

Adult blow flies create a plethora of disease potentials for humans, as they fly from dung and/or carrion to trash to your food. Blow flies are responsible for carrying the bacteria that causes dysentery, typhus, and cholera.

Signs You Have a Blow Fly Source Nearby

A single shiny fly that drifts in through an open door isn’t a problem. A steady stream of them, day after day, means something is feeding their young close by. Here’s what to watch for:

• Flies gathering at one window or in one room, often near the ceiling. That frequently points to a dead rodent or bird in the wall, attic or crawl space close by.
• Maggots on the floor. They’re cream-colored, legless and tapered at one end, and they crawl out from under baseboards, appliances or fixtures when they leave a carcass to pupate.
• Brown, barrel-shaped pupal cases in corners, under rugs or in insulation.
• Stains or damp spots on a ceiling or wall near an odor.
• Flies hovering over the trash can, dog run or compost bin outside.

Where to look: attics, crawl spaces, under decks and sheds, behind the refrigerator, garbage and recycling bins, and anywhere a pet eats or relieves itself.

What draws them: the smell of decay. Spoiled meat in a bin, old pet food and animal carcasses all attract egg-laying females.

When: blow flies are around most of the year in Florida, but hot, humid months speed up their life cycle, so a carcass can turn into a houseful of flies fast in summer. In North Florida, rodents that move indoors during cooler months can lead to an off-season burst if one dies inside. Next steps are on how to get rid of blow flies.