Females are kleptoparasitic and are especially attracted to predatory insects or spiders feeding on honeybees. Larvae develop for example in rotting vegetables.
Frons usually with a paired row of interfrontal setae situated on grey sclerotized interfrontal stripes; these stripes and concolorous frontal and orbital plates and ocellar triangle demarcating a dull to velvet-black M-shaped area. Subgenus Litometopa without 'M', frons with only one orbital seta and without interfrontal setae or hairs.
Head: Frons usually slightly longer than broad at vertex, especially in males. In most species (not in subgenus Litometopa) the M-shaped frontal vitta is velvet black, sometimes slightly subshiny, against which background the other parts of the front stand out distinctly. Postocellar setae parallel, ocellar setae lateroproclinate; 1-3 orbital setae, anterior orbital seta lateroproclinate (absent in Litometopa), middle seta lateroclinate and posterior seta medioreclinate and smaller or absent; interfrontal setulae present as well as setula between supra-antennal seta and eye margin. Antenna with basoflagellomere usually small and rounded, arista short pubescent. Proboscis geniculate, slightly elongate; labellum with 4 pseudotracheae.
Thorax: Acrostichal setulae scattered, usually 1 large prescutellar pair but up to 3 more large pairs between dorsocentral rows; 2 dorsocentral setae; 1 presutural setae; 1 postsutural supra-alar setae; 1 postalar seta; 1 postpronotal seta; 2 notopleural setae; anepisternum and anepimeron bare; 1 katepisternal seta; 2 scutellar setae. Basisternum large and V-shaped, precoxal bridge absent or present (Litometopa).
Wing: Hyaline; costa broken twice, shortly beyond humeral crossvein and at end of subcosta; costa extended to vein M1; discal cell separate from cell bm by crossvein bm-cu; veins A1 and CuA2 form cell cup, A1 ends shortly behind cell cup; A2 absent.
Legs: Fore coxa usually black, but yellow in flavicoxa group. Fore coxa and femur usually short, but in a few species slightly to strongly elongate and raptorial or mantislike in appearance.
Male abdomen: Black. Some variation in shape of sternite 5. Males of Litometopa have glandlike sclerotized structures within the abdomen (Brake & Freidberg 2003). Terminalia with surstylus partly fused with epandrium; cerci separate, nearly or as large as epandrium in lateral view; subepandrial sclerite present; postgonite absent; pregonite with a few setulae; phallapodeme fused with bases of pregonites and hypandrium, distiphallus membranous, forming a slender tube, which is widened in the middle.
Female abdomen: Preabdomen typical for Milichiidae. Ovipositor short, T6-7 and S6-7 undivided, S8 specialised and T8 short; S6 usually triangular, quadrate and with median anterior projection in Litometopa; secondary ovipositor inside segment 7 (see Brake 2000: 63). Spermathecal ducts rolled up into one small loose coil.