The unusual English and scientific names of Predicted Antwren stem from the discovery of this species: field ornithologists had predicted that a Herpsilochmus antwren "ought to occur" in southwestern Amazonia, before this species was discovered in life. This species now is known to be widespread, reported from a large number of sites between the Purus and Madeira rivers in Brazil, where it d primarily occupies relatively low stature forest on sandy soils near the edge of savannas, but its western and northern geographical limits have not yet been established. In appearance, Predicted Antwren resembles may other species in the genus: the upperparts are primarily gray, with a black crown, tail, and wings. It also has a conspicuous whitish supercilium, prominent white wingbars, and pale gray underparts. The sexes are similar, but the female has an orangish forecrown, and the crown has short white streaks. Predicted Antwren is most similar to its sister species, Aripuana Antwren (H. stotzi), which occurs on the east side of the Madeira River. Fortunately, these two species are readily distinguished by the pace and structure of the song. Little is known about the natural history of Predicted Antwren, but, like other species of Herpsilochmus, it is insectivorous, and pairs regularly join mixed species flocks foraging in the canopy.