Editing Sepsidae (section)

==Description==
[[File:Sepsis on blade of grass.ogv|thumb|''Sepsis'' sp. on grass (video, 59 sec)]]
[[File:Sepsidae 01.webm|thumb|Sepsidae mating dance, 4x-slow-motion]]
[[File:Sepsidae 03.webm|thumb|Sepsidae mating dance, 2x-slow-motion]]
For terms, see [[Morphology of Diptera]].<br>
Sepsids are slender flies that resemble minute, winged ants. They are usually black in color, sometimes lustrous, and sometimes with silvery hairs on the thorax. The head is rounded. Sepsids have one or more bristles at the posteroventral margin of the posterior spiracle of the thorax, a character that distinguishes the family from other [[Acalyptratae|acalyptrates]]. The postvertical bristles are divergent or sometimes absent. Up to three pairs of frontal bristles are seen. They have ocelli with ocellar bristles. Vibrissae and palpi are poorly developed. The front legs of the male often have extrusions, spurs, teeth, or other ornamentation. The tibia has a dorsal preapical bristle in most genera. The abdomen is usually constricted in the basal part.

The larva is slender, tapering at the front end, and smooth except for ventral creeping welts. The larva is amphipneustic: it has two pairs of spiracles, one toward the head and one at the tail. The bulbous posterior end with its pair of spiracles distinguishes it from the larvae of other acalyptrates.

The [[pupa]] is enclosed within a puparium.