• Blow and Bottle Flies Flies

    Blow and Bottle Flies
  • Blow and Bottle Flies
  • Blow and Bottle Flies
  • Blow and Bottle Flies


When you have blow and bottle flies in your home, you must locate and eliminate the source. A thorough housecleaning can usually prevent adults from finding other egg-laying sites inside. If there is a large population of adult flies, a quick spray with Maheu&Maheu Flying Insect Killer is usually all it takes.

If you observe large numbers of adult flies outside your home, your landscaping may be the culprit. Some plants use a subterfuge to trick blow and bottle flies, ensuring their own survival at the same time. These plants give off the subtle smell of rotting organic matter (not detectable by humans), attracting swarms of pollinator flies. We recommend relocating these plants away from your home.


  • Find and dispose of decomposing matter
  • Spot spray with pyrethrin-based insecticide in places with a lot of flies


  • Empty and clean garbage cans regularly
  • Make sure your bug screens are in good condition

Description and development

Blow and bottle flies are diptera in the Calliphoridae family. There are nearly 80 species in North America, but the most common are the blue bottle fly and green bottle fly. They can be easily recognized by the metallic sheen on their body. Blow and bottle flies grow to an average of 4 to 16 mm long.
Blow and bottles flies primarily lay their eggs on animal carcasses, but they may also lay them on other decomposing organic manner found in garbage. After a few hours, the eggs hatch and the larvae burrow into the carcass and live off the decaying flesh. When a larva matures, it moves away from its food source to make a pupa (cocoon). Eventually the metamorphosis is complete and the adult fly emerges from the pupa. Depending on the species, the life cycle (from egg to adult) takes two to three weeks in the right environmental conditions.


When these flies develop indoors, it generally indicates a dead animal in the vicinity—for instance, maybe a rodent has died in the walls of the building from the use of a rodenticide. All it takes is one fertilized female to lay her eggs in a carcass, and a few weeks later a hundred flies emerge. These flies can detect an ideal laying site from a few kilometers away. Adults are strongly attracted to ultraviolet light and often live on pollen and nectar. Like many species of fly, these flies are significant vectors of disease.


If you have used a rodenticide inside your home, consider removing it if possible. An animal could eat the product and die, rotting inside your home and becoming an ideal egg-laying site for blow and bottle flies. Despite claims to the contrary, there are no products on the market that can dry out an animal without any odor.

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