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.
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.
Scientific Name: Fannia spp.
Other Name(s): Latrine Fly
Fly or Mosquito
Size (Adult; Length): 1mm to 5mm (0.04in to 0.20in)
Note: An insect's reach is not limited by lines drawn on a map and therefore species may appear in areas, regions and/or states beyond those listed above as they are driven by environmental factors (such as climate change), available food supplies and mating patterns. Grayed-out selections indicate that the subject in question has not been reported in that particular territory. U.S. states and Canadian provinces / territories are clickable to their respective bug listings.