Even when dry, dirt is an effective abrasive as well as providing an incubator for mold. For the last several years Olin has been plagued by high humidity which has supported fantastic annual mold growths. Mold consumes the starch sizing in book cloth and paper and the collagen in leather. Insects Cockroaches visit the library for a drink of water, and then they stay to eat the animal glue used in the spines of books and the pizza fragments left by readers. Silverfish and firebrats, their heat resistant cousins, eat the starch sizing on the surface of paper and bookcloth.
Bookworms exist everywhere.
In New England the common form of bookworms are carpet beetles and their larvae. Dogs looking for bones use books as substitutes. Human factors Making photocopies can crack spines and break brittle pages. Each year thousands of books are highlighted, underlined, defaced, torn, cut out of their covers, dropped and generally abused. Exposed to rain and snow, pages stick together and covers become sticky.