As a collector and seller of antiquarian and secondhand books, I often discover the remains of dead book scorpions. The tiny arachnids are actually pseudoscorpions and are the book lover’s friend and mostly unseen companions. Although they are harmless to humans, these ferocious little bugs devour pernicious booklice and dust mites that damage books. If you discover a live book scorpion don’t kill it, just gingerly place it in an old book.