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.
One of the other features here is the number of fir and spruce trees which are damaged over the course of the winter. For some reason, it always seems to be the tops of the trees which fall off, leaving a tall pole left standing. When we got out to the field this spring, we found one had come off right next to one of our buildings, fortunately missing it, but obviously (to us) the rest of it had to be removed before it might come down and damage the building. So we called in our tree crew to remove it, and while they were doing that, I noticed that the fir right next to it had a series of big square holes dug into it, and the tree didn’t look all that healthy. I told the crew that “while you’re at it, you might as well get that one too.” Which, once they did, provided the answer to “why are woodpeckers digging these holes?”
Here’s the stump:
Lots of little holes all through the wood. What was making them? These:
Yes, carpenter ants. The reason the woodpeckers were making those holes was to get at them, their larvae, and pupae. In the first part of spring, the carpenter ants are providing (not by choice) a nice meal for the early arrivals. It also explains why the tree was looking “sick.” As for these ants? Well, they’re looking for a new home.