One of the sights you see in spring here in the Adirondacks is that some of the fir trees have big square holes dug into them. The explanation for them is that woodpeckers make them. The question I often had was: Why? You see, it’d be understandable if they were digging out a nesting hole, except that the holes aren’t high up, they’re usually waist level or lower. They’re also not obviously going after something like a grub which would be nearer the bark of the tree. This spring, I finally got my answer as to what was happening.