Blow Fly


Actual Size: ⅕”

Characteristics: Metallic; blue, green, gold to shiny black


  • Distinguished by their bright metallic appearance.
  • Adults lay eggs on the carcasses of dead animals.
  • Responsible for carrying the bacteria that cause dysentery, typhus, and cholera.


Blowflies are one of the most common flies found around dead animals. They prefer highly unsanitary habitats, and because of this, they may be vectors of disease pathogens, such as dysentery. These flies are distinguished by their bright metallic appearance and are abundant around commercial, institutional, industrial, and residential buildings when they are located near recycling centers, garbage dumps, slaughter-houses, and meat processing plants. Blowflies can pick up faint traces of odor of decay and can fly up to 12 miles from their source of origin in search of a suitable carcass to lay their eggs.

Blow Fly Habitat

Blowflies thrive best in weather that is warm and humid. They normally lay their eggs on meat, fish, or dead animals, but will also lay eggs in decomposing organic matter, like garbage, animal manure, decaying vegetables, grass clippings, and poorly managed compost piles. Under ideal temperatures, blowflies can develop from egg to adult in as little as 7 days. Many homeowners have witnessed this behavior as a mass emergence of maggots crawling from their backyard trash cans when kitchen waste placed in these trash cans was not sealed in a plastic trash bag.

Blow Fly Behavior – Threats – Dangers

Blowflies do not bite or sting. They are, however, strongly attracted to human foods and garbage, making cooking outdoors difficult when they are present. As with house flies, they may be involved in the transmission of disease agents acquired from garbage or animal feces and subsequently deposited onto human foods. The primary threat from blowflies is the distribution of disease-carrying organisms that affect humans such as salmonella food-poisoning, Dysentery, Cholera, various parasitic worms, and many others.

Blow Fly Prevention

The best preventative measure to deter a blowfly infestation is to properly dispose of any decomposing animal remains where blowflies might lay eggs. Dead animals such as birds, cats, dogs, and opossums should be buried at least 12 inches deep or placed in garbage bags that are tightly tied. Removing all food residues and cleaning garbage cans weekly will also make the cans less attractive to blowflies. Keep windows screened and doors closed to keep flies from entering a home. Sticky traps and ultraviolet light traps placed around homes and businesses can reduce blowfly populations.