Eric Bgin on FlickrThe animal kingdom is a cacophony of grunts, growls, whistles, squeaks, and other noises that sound utterly crazy to the human ear but are essential to animals survival. We know ...

Even in the wild, though, the solitary porcupine is known for a wide range of noises, from squeaks and grunts to whistles, shrieks, and even “tooth clicking.” ...