Next time you are putting on your makeup and are about to put on mascara: all mascara is made from bat guano. (in other words - bat feces, bat poop). (source: Billy the exterminator, Vexcon) UPDATE: My bad! I goofed, I didn't follow my own rule of 'check it out before passing it on'. It really isn't true after all. It is true that Billy said that on his show, but he was wrong. But now it is making the rounds of the internet as true. Sorry.