Insect Identification
Insect Identification

Small House Fly - (Fannia spp.)

Authored By Staff Writer | Last Updated: 8/28/2014

Small House Flies are annoying because they are attracted to food and toilets, but their affinity for corpses makes they quite useful to Forensic Entomologists.

Picture of Small House Fly

Male Small House Flies form swarms in the summer. Females lay their eggs in animal/human feces or on dead and decaying animal tissue. For this reason, one species (F. scalaris) is also known as the Latrine Fly and is considered a potential harbinger of disease because after landing on feces, they land on food as well.

Though they are half the size and much thinner than a normal House Fly (Musca domestica), the Small House Fly shares similar traits. The life cycle of F. scalaris is well-known and the maggots (larvae) develop on feces or decaying tissue. Forensic scientists use this knowledge to gauge the amount of time a corpse has been decomposing. Identifying which part of the life cycle the maggots/flies are in when they are found on a body helps calculate when the person died.

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Category: Fly or Mosquito
Common name: Small House Fly
Scientific Name: Fannia spp.
Other Names: Latrine Fly

  Kingdom: Animalia
   Phylum: Arthropoda
    Class: Insecta
     Order: Diptera
      Family: Muscidae
       Genus: Fannia
        Species: spp.

Adult Size (Length): 1mm to 5mm (0.04in to 0.20in)

Identifying Colors: black; red

Additional Descriptors: tiny; hairy; flying

North American Reach (Though Not Limited To*): Alabama; Alaska; Arizona; Arkansas; California; Colorado; Connecticut; Delaware; Florida; Georgia; Hawaii; Idaho; Illinois; Indiana; Iowa; Kansas; Kentucky; Louisiana; Maine; Maryland; Massachusetts; Michigan; Minnesota; Mississippi; Missouri; Montana; Nebraska; Nevada; New Hampshire; New Jersey; New Mexico; New York; North Carolina; North Dakota; Ohio; Oklahoma; Oregon; Pennsylvania; Rhode Island; South Carolina; South Dakota; Tennessee; Texas; Utah; Vermont; Virginia; Washington; West Virginia; Wisconsin; Wyoming; Alberta; British Columbia; Manitoba; New Brunswick; Newfoundland and Labrador; Nova Scotia; Ontario; Prince Edward Island; Quebec; Saskatchewan; Mexico

* Keep in mind that insect reach is not governed by lines on a map and therefore may appear in areas/regions/states beyond those listed above.