They are winged or wingless ectoparasites of bats, and often have long legs.

The streblid subfamily Trichobiinae may be more closely related to the Nycteriboscinae and other lineages in the Nycteribiidae.

Alternatively, the Streblidae and Nycteribiidae might be united as a monophyletic family containing all bat flies.

[1] Subfamilies are here listed in presumed order of most ancient to most recently evolved.

One of the characteristic feature of streblid bat flies is their variable degree of eye reduction.