Most species of wrens forage in the understory, or even are terrestrial, but the two species of Odontorchilus have very different habits: Tooth-billed Wren of Amazonia and Gray-mantled Wren (Odontorchilus branickii) both occupy the canopy of tall forest. Tooth-billed Wren is a small, slender wren with a long narrow tail, and is dull gray above and pale buff below, superficially resembling a gnatcatcher (Polioptila). This species generally is uncommon, and is found only in central Brazil south of the Amazon and in adjacent northeastern Bolivia. The "tooth" on the bill for which this bird is named is only a small notch, and is not apparent in the field. Tooth-billed Wren typically forages in pairs that are associated with mixed species, but otherwise the natural history of this interesting species is almost completely unknown.