Blow flies stand out from other common flies thanks to their shiny, metallic blue or green body, which can almost look iridescent in direct sunlight. They’re slightly larger and stockier than a house fly, typically around a third to half an inch long, with a loud, heavy buzz that many homeowners notice before they even see the fly itself. Their bristly bodies and rounded heads with reddish eyes are additional clues that separate them from the duller gray house fly.
Blow flies are drawn overwhelmingly to strong odors, particularly decaying organic matter, which is why they tend to appear suddenly and in numbers when something has gone wrong on a property. Around Los Angeles and Orange County homes, this often means trash and dumpster areas, pet waste left in yards, compost bins, or — less commonly but notably — a dead rodent or bird trapped in a wall void, attic, or crawl space. Properties in Norwalk, Carson, and Long Beach with exterior trash storage or nearby alleyways sometimes see recurring activity if odor sources aren’t fully addressed.
Because blow flies move directly from decaying matter to any exposed surface nearby, they’re considered a genuine sanitation concern. They can carry bacteria on their legs and mouthparts and deposit it on countertops, outdoor dining areas, or food left uncovered. A sudden cluster of blow flies indoors, especially in a room where none were expected, is also one of the more reliable early signs of a hidden dead animal that needs to be located and removed.
Guarantee Pest Control has helped Los Angeles and Orange County property owners track down the source of blow fly activity since 1958. Because these flies point directly to an odor or decay source, our technicians investigate thoroughly — checking attics, wall voids, crawl spaces, and exterior waste areas — before recommending an effective treatment plan, with eco-friendly Guarantee Green options available. We provide free estimates, no-penalty cancellation, and a 3-month guarantee on most services. If you’re noticing a sudden swarm of shiny, buzzing flies, don’t wait to find out why — call 1-800-507-3787 or request a free estimate at /get-a-quote/.