Yeah, right! There are bugs that eat your bow hair if you don't open the case often enough?
Sounded like some boogie-man story used by frustrated string teachers to scare students into practicing everyday.
They are REAL!
Have you ever pulled a bow out of a case (that maybe hasn't been opened for a while, ahem) only to find the bow hair is totally falling out?
But, now that I am a teacher myself, I just can't help saying:
Practice every day and the bugs will stay away!
That's by far the best insurance.
Also, be sure to clean any cases you happen to purchase on CRAIGSLIST. Probably a good policy anyway...