Singular animated books are trivial for most wizards to create, a cantrip performed to impress the layman, or for practical household purposes. It was discovered, however, that in certain magic-rich conditions, a collection of tomes could develop limited sentience on its own, individual books behaving as fish in a larger, interdependent school. Swarms of books have since become many arcanists' favored trap to unleash against undesirable snoops, turning knowledge against those who would steal it in a very literal fashion.

A swarm of books can exist dispersed at rest, strewn across the workspaces of absent-minded wizards or shelved away in disparate sections of a grand library. When the volumes waken, they aggregate together in a whirling storm of pages, swarming unsuspecting trespassers to deliver death by a thousand paper cuts. Wizards delight in animating particularly important tomes with this defense, knowing that a thief would have to decide between risking life and limb to obtain them, or destroying them and surviving.