While I was trying to make a Minecraft map based on a big library and I had the idea to populate it with these things
They just stand until someone needs help to get a book, then they'll do everything possible to get the required book. Another action is that they will attack anyone that tries to damage high quantities of books, if the endangered book is destroyed they will become passive, if the person leaves the book they will become passive.

Hope you had a great day, and please give it some love and diamonds.