I've had some feathers eaten by mites or something from time to time. I'm not enough of an expert to say exactly what was eating them. I've never treated the arrows to try to stop it. What I noticed was a little bit of eating, and then it stopped. It's like some bugs hatched, ate, and then either died or flew away. If they flew away, they didn't come back. My guess is that they probably died, or I would see more eaten spots on the feathers. Anyway, it's just a thought that maybe if you do nothing, it will stop on it's own.