Silverfish are drawn to dry starchy substances commonly found in pantries. The glue that binds old book pages together is also appetizing to Silverfish. This explains why they might also be found in the pages of old books, or running around libraries: the printing material used in these items is a food source. Amazingly, Silverfish can live for months without eating. They are harmless to humans, though their presence is usually considered a nuisance.
Silverfish bodies are covered with flexible and slippery scales that protect the insect from capture from larger insects such as spiders. This body covering also allows them to neatly fit within the binding edge of a closed book and feed on the paste.
Another interesting facet about these critters is in the time that they take to mature. Southern Silverfish can see adulthood in 24 months whereas Northern-based Silverfish will take longer. No doubt this is due to the warmer temperatures of the Southern states.