Very small bird of humid tropical forest and edge. Favors vine tangles at mid-upper levels, where moves actively, holding its tail cocked and flopping it from side to side. Appearance is distinctive, with buffy face, very long thin bill, and fairly long tail with white tips. Similar to Chattering Gnatwren but lacks the extra white spots on outer tail feathers. Easily overlooked, but rising and falling trilled song reveals its presence.