house fly

House fly (Musca domestica). Photo: Joseph Berger, Bugwood.org

Updated: July 2, 2026

House flies

A red-eyed fly with black stripes on a gray body sites on a piece of fabric.
House fly. Photo: Matt Bertone, NC State University

These are the most common fly found in and around homes.

  • Adults are about ¼ inch long and dull gray in color.
  • Larvae (maggots) are ¼ to 3/8 of an inch long when mature. They are whitish in color, have no eyes or legs, and taper towards the front (head end).
  • Food sources are varied, and include excrement and human food.
  • Adults use their mouthparts to liquefy food before ingesting it, and can mechanically transmit many disease pathogens.
  • Egg-laying female flies will seek out any warm, moist material that has sufficient food for larval development.

House fly management

  • Locate and eliminate larval breeding sites. Remove trash promptly or or secure trash by using cans with tight-fitting lids. Keep garbage cans as dry and clean as possible.
  • To prevent adults from entering homes, secure window and door screens and look for gaps in weather-stripping that need repair. Seal all holes (gaps/cracks) and other entry points; make sure all vents are tightly screened.
  • Adult flies can be trapped with baited fly traps or sticky fly tape.
  • Insecticide spraying is generally not effective or recommended inside the home.

Blow flies, green bottle flies, and blue bottle flies

  • Blow flies and bottle flies are similar in size to house flies, but are have metallic blue or green body colors.
  • These flies may breed in dead animals, feces, or garbage, depending on the species.
  • If a large number of these flies are found in the house, they are usually breeding in the home or in the immediate area. Examples of breeding sites may be a dead mouse or squirrel in the attic or a dead bird in the chimney. Green bottle flies are commonly seen on pet feces outdoors.

Blow fly and bottle fly management

  • The life cycle is very short (2 to 4 weeks).
  • As with the house flies, it is important to locate and eliminate the larval breeding site. This may involve timely removal of pet waste from the yard, locating a dead animal, or cleaning up garbage cans.
  • Adult control is the same as for house flies: trap them with baited fly traps or sticky fly tape. Insecticide spraying is generally not effective or recommended inside the home.

Examples of blow flies and bottle flies

A fly with large red eyes and a metallic yellow-green body sits on a leaf.
Blow fly (family Calliphoridae). Photo: Johnny N. Dell, Bugwood.org
A grayish-black colored fly with red eyes sits in a laboratory container.
Blue bottle fly (Calliphora vomitoria). Photo: Joseph Berger, Bugwood.org
A red-eyed fly with a white face and metallic bronze-and-green body sits on a leaf.
Common green bottle fly (Lucilia sericata). Photo: Joseph Berger, Bugwood.org
A red-eyed fly with a metallic teal-blue body sits on a piece of fabric.
Blow fly (family Calliphoridae). Photo: Matt Bertone, NC State University
A red-eyed fly with a metallic yellowish-green body sits on a leaf.
Green bottle fly (Lucilia species). Photo: David Cappaert, Bugwood.org
A pinned fly specimen with a metallic blue-green colored body.
Common green bottle fly (Lucilia sericata). Despite the name, they can also be metallic blue-green in color.
Photo: Paul Langlois, New World screwworm and other calliphorids (Diptera), USDA APHIS PPQ, Bugwood.org