Woodpeckers peck for three main reasons: to find food, to create nesting sites, and to communicate. They peck wood to uncover insects and larvae living inside the bark or wood, which serve as their food. Woodpeckers also excavate holes in dead or dying trees to build nests, creating cavities in the tree trunks. Additionally, woodpeckers use rhythmic pecking, known as "drumming," to establish their territory and attract mates. This drumming can occur on wood, metal, and other hard surfaces to create loud sounds for communication.