This is a Pileated Woodpecker pecking on the power pole in our front yard. There are several reasons that woodpeckers peck on wood. What are they?
Answer:
If you see (or hear) a woodpecker slowly tap-tap-tapping as it moves along a tree, it is hunting for insects.
If the woodpecker is tap-tap-tapping in one place, it has either found some yummy insects, or if it stays for a long time, it may be carving out a nest hole.
Some woodpeckers, such as the Yellow Bellied Sapsucker, make holes in trees so that they can drink the sap and eat the nutritious inner layer of bark.
If you see or hear a woodpecker making a loud BRRRRRRRRR sound as it rapidly pecks the tree, it is communicating with other woodpeckers, either to claim territory or to attract a mate. Because they are trying to make a loud noise, they will often do this on metal vents.