Anyone have any experience with these? While I was home on vacation in August I kept hearing what sounded like a squirrel scraping its teeth on a nut, but it was coming from one of my pines in the corner of my yard, and I never saw anything. Once I got to thinking about it, the tree didn't look as healthy as the other pines. Do these beetles make enough noise that maybe that was what I was hearing? If so, what can I do to keep my other trees safe, if anything?