It's possible you have encountered bow bugs before without knowing it. The most obvious sign of a bow bug infestation is if you have a bow that seems to have lost a bunch of its hair all at once or the hair is falling off in clumps.
That's because the bow bugs have been happily munching away at it. You might even see some of the hair sticking out of the case.
So what are bow bugs? Bow bugs, or dermestids, are part of the beetle family. They can be found anywhere in your house and as small larvae they enjoy eating natural fibers like bow hair. If you have a violin case with a bow in it that hasn't been opened for a long period of time, then your chances of bow bugs finding their way into your case are pretty high.
Bow bugs enjoy being in dark, uninterrupted spaces. As they grow in size they molt and leave casings of their shells that are a couple of millimeters long, so you may encounter some of their casings in the crevices of your violin case.
If you do encounter bow bugs than you shouldn't panic as they are relatively easy to get rid rid of. Your first step in getting rid of them should be to vacuum out your case thoroughly paying close attention to the narrow crevices. Bow bugs don't like light so leaving your case out in the sun for a while is a good way to get them to leave your case. Cedar essential oil is a great natural bug repellent so putting a couple of drops of it in your case or putting a small cedar shaving sachet in it can work wonders.
You can also spray the inside of the case with a pest repellent safe for cloth like Repel Permanone or Sawyers Permathrin. Make sure the case is completely dry before putting anything back in it. Some places may suggest throwing a moth ball in the case but it is not the safest option. Moth balls contain neurotoxins and can leave traces of them on your instrument which are not healthy for you to be inhaling as you practice.
As for the bow itself, bow bugs usually won't damage a bow beyond just eating all of the hair away, so a simple rehair will suffice if you want to start using the bow again.
Bow bugs may be gross, and finding that you have an infestation may be somewhat unnerving, but your shouldn't be upset or embarrassed. Bow bugs are a common problem that can be solved pretty easily.