Typically found singly or in pairs (Ridgely and Tudor 1989), Rufous-naped Greenlets forage with mixed-species flocks in forest canopy and subcanopy (Hilty 2003). They glean actively on foliage and outer twigs, frequently hanging upside-down to search for insects on the undersides of leaves (Hilty 2003, Ridgely and Tudor 1989). Rufous-naped Greenlets often occur near the center of large mixed-species flocks, and may be a nuclear species in mixed flocks within its limited range (Colorado 2011, D. Slager personal observations). The species at least occasionally attends swarms of Neivamyrmex army ants (Gochfeld and Tudor 1978). Rufous-naped Greenlets are active and not shy, but because of their small size and canopy-dwelling habits they are often first detected by voice (D. Slager personal observations).