Final answer:
Walter carries his books home from the library in a brown paper bag to hide his interest in reading from the neighborhood boys.
Step-by-step explanation:
In the selection from Bad Boy, Walter carries his books home from the library in a brown paper bag because he does not want the neighborhood boys to see that he likes reading. This is evident in the text when Louisa changes the position of the books and Dagget questions why it matters. Walter carries his books in a brown paper bag to hide his interest in reading, as he faces judgment and teasing from his peers for being a book lover.