[1][7] These flies are found in damp places throughout the world, and many species form dense swarms in suitable habitats.

The antennae are, in most species, 14- or 16-segmented (rarely 6-, 10-, or 17-segmented), usually verticillate (whorls of trichia) and only exceptionally ctenidial or serrate (Rhipidia).

There is a distinct V-shaped suture between the mesonotal prescutum and scutum (near the level of the wing bases).

The genitalia of males have large separated gonocoxis and one or two pairs of appendages which are sometimes greatly folded (Dicranomyia, etc.).

Limoniids occupy a wide range of habitats and micro habitats: in earth rich in humus, in swamps and marshes, in leaf litter and in wet spots in woods (numerous genera and species); in soils with only moderate humus content along stream borders (Gonomyia Meigen, Rhabdomastix Skuse, Arctoconopa Alexander, Hesperoconopa Alexander); in dry to saturated decaying wood in streams, where the larvae feed on fungal mycelia (Gnophomyia Osten Sacken, Teucholabis Osten Sacken, Lipsothrix Loew); in decaying plant materials (various subgenera and species of Limonia), in woody and fleshy fungi (Limonia (Metalimnobia Matsumura); in fresh water, especially rapidly flowing streams (Antocha Osten Sacken, Hesperoconopa Alexander, Cryptolabis Osten Sacken); intertidal zones and brackish water (Limonia (Idioglochina Alexander, Limonia (Diuanomyia) Stephens); freshwater aquatic environment during the larval stage and nearby margin areas for pupation (Limonia Meigen, Thaumastoptera Mik, many Pediciini, Limnophilinae, and Eriopterini); steep cliff faces supporting a constantly wet film of algae (some species of Limonia Meigen, Orimarga Osten Sacken Elliptera Schiner); in moist to wet cushions of mosses or liverworts growing on rocks or earth (various species).

[16] Another specimen (Limonia dillonae) preserved in amber in the Raritan-Magothy Formation suggests limoniids have been extant since the Upper Cretaceous period.