The battle between book scorpions and booklice has been going on for as long as mankind has been reading books. The book scorpion -- actually a tiny member of the arachnid family -- lives among old books, where it hunts pesky booklice. For their part, booklice are attracted to books because of the starch used in the glue by bookbinders. If it weren’t for book scorpions, these lice would run amok, dismantling books one spine at a time.
Technically, a book scorpion is a pseudoscorpion. Pseudoscorpions are generally beneficial since they prey on a variety of pests, such as the larvae of clothes moths and carpet beetles, ants, mites, and small flies -- in addition to booklice. They’re rarely seen due to their size. However, book scorpions are slowly disappearing from dusty bookshelves. This is because modern books are bound with synthetic glue, which doesn't seem to interest booklice.
Pseudoscorpions to the rescue: