Uncommon, rather large woodcreeper of humid tropical forest; infrequently seen away from ant swarms. Found singly or in twos and threes, often with Tawny-winged and Ruddy Woodcreepers at army ant swarms. Perches upright on trunks at all levels; often rather sluggish. Often looks dark and plain overall, with dark mask and pale base to stout bill. Dark barring on head and body visible with good views. Loud whistled song given mainly around dawn, a whistled “too’ih tooh’ih.”