[2][3] There are scant records of chloropids from amber deposits, mostly from the Eocene and Oligocene periods although some material may suggest the family dates back to the Cretaceous or earlier.

Sometimes this sclerite is reduced and rarely membranous swellings occur in this region, which are usually retracted and visible only in macerated specimens.

See [1] Larvae are mainly phytophages of Poaceae, Cyperaceae, and Typhaceae; they develop inside the vegetative or reproductive parts, sometimes directly in the inflorescence or seeds.

In a small number of species the larvae are predators and live in the egg cocoons of spiders, praying mantis, or the nests of locusts.

Species that occur in large numbers and are attracted to animal secretions such as tears and dung, sometimes cause serious irritation and infection.

Prominent examples include the eye gnat genera: Liohippelates in the Americas and Siphunculina in parts of Asia.

In warm seasons they may emerge in huge numbers and swarm about the eyes, up the nostrils and in the mouths of mammals, including livestock and humans.

Bacterial examples, in particular in the Caribbean and parts of South America, include the transmission of Treponema pallidum pertenue, the spirochaete that causes yaws.

[5] Haemophilus influenzae biotype aegyptius is the pathogen that causes the highly dangerous Brazilian purpuric fever; in children it usually is rapidly fatal, and various species in the family Chloropidae are potential transmitters of the disease.

[5] Apart from bacterial pathogens, Chloropidae also may transmit viral diseases; in particular they have been shown to carry the vesicular stomatitis virus.

[5] Though Chloropidae generally do not attack vertebrates directly, the larvae of the Australian frog flies, genus Batrachomyia, are exceptions.

The larvae burrow under the skin of the body rather than the head or legs, and there they form visible swellings in which they lie as parasites, presumably feeding on blood and other bodily fluids.