Certhia

Genus of tree creepers, family Certhiidae, order Passeriformes. It includes several species of bird with moderately long curved bills, short wings, and stiff tail-feathers that they press against the bark as a support. The birds have large feet and strong claws well-adapted for climbing about trees and rocks; there is a sharp claw on the hind toe. They are almost exclusively insectivorous, although they eat small seeds in winter.