Bookworms Are Literally Real Insects

While the term 'bookworm' fondly describes an avid reader, its origins are far more destructive. The title originally belonged to the larvae of several insect species, most notably the common furniture beetle and the deathwatch beetle. These tiny grubs don't consume the stories themselves, but rather the materials they are printed on. They tunnel through pages, feeding on the cellulose in the paper and the starchy glues and pastes used in traditional bookbinding, leaving a trail of tiny holes and fine dust known as 'frass'.

For centuries, these pests posed a significant threat to libraries and archives, capable of turning irreplaceable manuscripts into lace. The deathwatch beetle earned its ominous name from the quiet, repetitive ticking sound it makes—a mating call that, when heard in the silent vigils beside a deathbed in old timber-framed houses, was superstitiously thought to be an omen. The damage could be so extensive that a single larva could bore a straight tunnel through an entire volume left undisturbed on a shelf. To combat these literal devourers of words, fumigation and the application of pesticides became essential, if sometimes harsh, practices in book preservation.