And here I thought that I was somehow exceptional. I built my first horn in the 70s, and after decades of use, went on to another. After a few years of storage behind the breadmaker on the kitchen counter, I noticed the same holes and gnaw tracks covering the horn surface. I have some dark epoxy and fil and finish is on my list of winter projects.
I have some pyrethrins that would make excellent bug treatment for all mo other horns.