Why do woodpeckers peck on trees?
Woodpeckers are named for the method in which they find food: pecking, hammering and digging in wood to reach insects, grubs, and even sap. But woodpeckers also use their bills to excavate holes in which to live and nest. They also hammer on tree trunks to advertise their territory and presence to other woodpeckers. Woodpecker territorial drumming increases in frequency in the early spring months, before the breeding season.
