Most woodpeckers are protectors of forests. They eat harmful insects and grubs that live beneath tree bark. The woodpecker finds food by hammering on wood. It drills with its sharp beak, and then "harpoons" insects with its pointed, barbed tongue. Nuts and berries form a small part of its diet.
All woodpeckers nest in holes of trees and poles. All lay white eggs. Short, stiff tails, and four-toed feet support their bodies as they cling to tree trunks. The northern black-backed and boreal woodpeckers are the only types with three toes and without some red coloring. The yellow-bellied sapsucker girdles trunks with borings and thus is one of the few woodpeckers that could prove harmful to trees.