Here is a little known fact about the origin of the word "woodpecker."
Oddly enough, it has nothing to do with the fact the bird actually pecks
the wood but rather with the quantity of wood it pecks.
A woodpecker removes a large amount of wood from a tree or cactus in its
search for grubs, insects and sap. The cavities are used as roosting
holes and, in the mating season, serve as nesting places.
Ornithologists studying the birds were curious to know how much wood
a bird typically removed. Instead of trying to collect what the birds
had removed, they simply refilled the holes with sawdust. The sawdust
was carried in small barrels called pecks, named because the amount
a peck carried was a peck, i.e., about two gallons. They found some
holes needed nearly a barrel-full of sawdust. It so amazed the
naturalists that a bird could remove such a quantity of wood they
named it a "woodpecker." Although the name only applied to some
species of the bird, the name stuck to all.
"How much wood would a woodpecker peck if a woodpecker would peck wood?"
That ancient riddle has never been answered (until now, that is).
Answer: "A woodpecker would peck a peck of wood if a woodpecker would peck wood!"