Cave Balls
The four of us had nearly finished scrambling through a New Mexico cave when we came across a clear pool blocking our path: we were forced to wade to the exit. We noticed the bottom of the pool was littered with numerous white balls.

The mystery began to gnaw on us: what were these ghostly, golfball-like spheres? We touched one ball, and the white coating suddenly popped and drifted away, leaving a central mudball-like core with what appeared to be little sticks poking out. In the flickering light, we could see there was some kind of strange gas streaming away from the mudball, which just deepened the mystery. We combined our brainpower to decipher the mudball's mystery.

It took a long, long time, passing the mudball back and forth from hand to hand, sniffing the gas, and reaching into the waters to gather other popping mudballs, to finally realize that THIS is what ultimately happens to bats that die and fall into limpid cave waters.
(Perv With A Dog had his eyes pecked out by scrub jays on, Mon 4 Jul 2005, 0:40, Reply)