Lots of places that don't have light, but have paper and a nearby source of water, will likely eventually have either carpenter ants or termites. They got into my grandparent's built-in bookshelves, and the books on them.
Almost as important as the 'words' found in the books are the 'pictures'. Sure, you can get pictures on the internet, but the people who OWN or took the pictures get nothing (usually).
Once a year I remove all my books off the shelves, spray with pest spray until wet, let it dry (or wipe dry) and then put the books back. Waaaaaaay too many rare ones to let get damaged by bugs.
And as us book owners know, there are a great many thousands of rail photos in books that are nowhere to be found on the Internet. As I age, I wonder about the destiny of my rail book library when I pass away someday. I've given my wife the name of a rail book reseller.
A local (Australian) spray called Mortein, specifically their crawling insect spray. It is strong. In fact this afternoon I was in the workshop cleaning out old cables and picked up a manila folder and a heap of silver fish ran onto my arm and jumper. Knowing I had to return to the house with possible silver fish eggs on me I sprayed Mortein on my arm and sleeve of jumper. I still had more stuff to move in the workshop so kept on working. After about an hour I was not feeling well at all , , that stuff works ! Books are safe
It is one of my worries too. I've spent a lot on books and gone to a lot of trouble to protect the books and dust jackets. Yet time and time again I hear of whole collections being thrown out , nobody seems to know much about titles and what they are worth. I've also seen clubs dispose of books without checking values or rarity with a worst case of 4 books easily able to fetch $1000 (US$750) just gone , missing , never seen again. Another thing I do (or rather don't do) is lend books. I know I've offended a few people by refusing to lend them and instead offered them to come visit me and can read all they want. I still get other friends complaining that they've leant books out and never seen them again.
Through the years I loaned books, artifacts, photos/slides, railroad documents, timetables and more. Far, far too many never came back. (Some I know who has them, but they won't return MY property! In one case it took 7&1/2 years to get five slides back from a book author.) Or the credit I was promised in an article or book never appeared. Or the magazine/book promised in return for efforts expended never materialized. Yet I kept doing it. (As the old saying goes "nice guys finish last!") I finally quit and started refusing. Wow. What a reaction. I became the Bad Guy. Really? What a messed up world we live in, when people cannot understand...
Unfortunately my old collection of books and CDs (trains and autos) were lost in a fire. I haven't done much replacement since. Many bug sprays are not only bad for your body but also the books. You found what it can do for you. I can also cause the books to age rapidly. If possible try getting something dry. Like is put on flowering plants.
That is eucalyptus (epsom salt). It's granular but can be crushed down finer to dust the shelves. But wash it off you. Soon.
