Skeleton

Then he heard it.
Deep down in the subterranean fissures of his body, the minute, unbelievable noises; little smackings and twisting and little dry chippings and grindings and nuzzling sounds like a tiny hungry mouse down in the red-blooded dimness, gnawing ever so earnestly and expertly at what might have been, but was not, a submerged timber ... !

Ray Bradbury