Phorid flies can often be identified by their escape habit of running rapidly across a surface rather than taking flight.

The third segment of the antenna is large and rounded or elongated, and bears a long apical or dorsal arista directed sideways.

An important taxonomic character is the precise location of the anterior spiracles on the pleura of the thorax.

In some genera, segments VII to X in the female are highly sclerotized and extended into a tube ("ovipositor").

Traditionally, phorids were classified into six subfamilies: Phorinae, Aenigmatiinae, Metopininae (including tribes Beckerinini and Metopinini), Alamirinae, Termitoxeniinae, and Thaumatoxeninae.

Disney rejected the entirety of Brown's work, deeming it premature, and a lively debate ensued.

Some species feed on bracket and other fungi and mycelium or on living plants (sometimes as leaf miners).

Some are predators or parasites of earthworms, snails, spiders, centipedes, millipedes, and insect eggs, larvae, and pupae.

The adults feed on nectar, honeydew, and the juices exuding from fresh carrion and dung.

Some adults feed on the body fluids of living beetle larvae and pupae, others prey on small insects.

Because they frequent unsanitary places, including drain pipes, they may transport various disease-causing organisms to food material.

Although it does not cause direct damage, it is an efficient vector of dry mould (Lecanicillium fungicola).

Phorid flies develop from eggs into larval, and pupal stages before emerging as adults.

The larvae emerge in 24 hours and feed for a period between 8 and 16 days, before crawling to a drier spot to pupate.

[10] Other species, especially those of the giant genus Megaselia, develop in various fungi during their larval stage and may be pests of cultivated mushrooms.

Commensal myrmecophilous phorids most often live in waste piles, consuming food discarded by the ants.

Parasitoid phorids typically attack foraging ants, using a species-specific strategy to land on a host and inject eggs within seconds using a sharp ovipositor.

The nature of the myrmecophily observed in certain species of phorid flies is unknown, such as the recently discovered ant larva-mimicking genus Vestigipoda, which live in brood piles and may feed on ant brood or receive care from nursing workers.

The first instar larvae migrate to the head, where they feed on the ant's hemolymph, muscle and nerve tissue.

Eventually, the larvae completely devour the ant's brain, causing it to wander aimlessly for about two weeks.

Various species of Phoridae have been introduced throughout the southeast United States, starting with Travis, Brazos, and Dallas Counties in Texas, as well as Mobile, Alabama, where the non-native fire ants first entered North America.

Pseudacteon has a predominantly indirect effect on fire ant populations, as they do not destroy colonies outright by killing off large numbers of ants; rather, the presence of Pseudacteon in the vicinity of foraging trails elicits a significant defensive response which effectively distracts foraging workers and may reduce the colony's competition with native species.

[15] In January 2012, a researcher discovered larvae in the test tube of a dead honey bee believed to have been affected by colony collapse disorder.

Infected bees act oddly, foraging at night and gathering around lights like moths.