Treecreepers measure from 12 to 18 centimetres in length. Their bills are gently down-curved and rather long, used for probing bark for insects and spiders. They often climb up tree trunks in a helical path, hopping with their feet together their toes are long and tipped with strongly curved claws for gripping. The longer tails of the Certhia treecreepers are stiffened to use as a prop while climbing, but those of the spotted creeper are shorter and not stiffened. Their songs and calls are thin and high-pitched.