How much beating and humidity do mics take?

[MiniMan]

I was just wondering, how much do these mics take before something terrible happens? A rain cover for mics would be pointless because of the tapping sound from the raindrops, but is there any way to use mics on rainy days? And also, I've heard that you should never, and absolutely never, bump the mic into anyhthing. Is it really that fragile?

 

[bwest]

do a search on 'hogs hair' for rain