Books and rats? They go together like Oreos and milk… at least in this story. Books are very important in Rats because books provide the rats with the knowledge they need to change their lives.
When the rats arrive at Boniface, they gravitate to the library because it is, typically, filled with books. Nicodemus explains that they "fell on those books with even more appetite than on the food" (18.27). Since we all know that rats love to eat, this must mean that they really loved these books. And every time they get to reading, we can't help but notice that it gives them a big fat dose of knowledge and power. Take for example when Mrs. F goes into the rats' library and sees how many "stacks of books" there are (11.53). She is amazed by the electricity, sure, but the books really hammer home how smart and exceptional the rats really are.
Even though books contain powerful information that the rats need, they also have the power to cause pain:
Most of the books were about people; we tried to find some about rats, but there wasn't much.
We did find a few things. There were two sets of encyclopedias that had sections on rats. From them we learned that that they were about the most hated animals on earth, except maybe snakes and germs. (21.9)
Learning about how hated they are is a major bummer for the rats, who feel like this is really unfair because they are super-rats after all. But, hey, there's an upside to all of this: despite the fact that this hurts their feelings, it's information that they absolutely need to know in order to survive. The books are more than just a way to show that these rats have some serious brainpower. The knowledge inside them helps the rats to develop a plan to be free of the humans who hate them. In that sense, reading and books are the keys to survival for our furry friends.