Yes, we know ... YUK! But whether you see them or not (usually you never will) most every house, especially in warmer climates, has them. They're also called carpet beetles. They're very small; MUCH smaller than this photo.
Bow bugs, also known as carpet beetles and bow mites, are larval-stage members of the Dermestidae family. They’re fairly common, even in scrupulously clean homes, and they love to eat bow hair as well as wool.
It is important not to store your bow in an unopened case for long periods of time, because bow bugs do best in dark, enclosed places.
If your bow hair is getting brittle or breaking anywhere in the middle, bow bugs have infested your case. You must have the bow rehaired, and you or the luthier must clean and disinfect your case. Just follow these easy steps to be bow-bug-free:
Get rid of them.
Vacuum your case thoroughly, at least twice (or have the violin shop do this).
Leave your case open in a well -ventilated, bright area for a day or two.
Take your bow to be rehaired professionally. If the hair isn’t yet broken, be sure to tell them about the bugs so they can take steps to protect the other bows and cases in the shop. (They won’t think you’re bad for having bow bugs; they’ve seen many before.)
Keep them from coming back.
You can try putting cedar chips or moth balls wrapped in cloth in the case, but nos. 2 and 3 below are most important. Don’t use an insecticide spray; the residue could damage your instrument and bow.
Make a practice of periodically leaving your case open in a well-ventilated, bright area.