Punny Chicken

A chicken walks into a library and straight up to the librarian. The chicken says "book, book" so the librarian humors the chicken and gives him a book. Off goes the chicken out the door.

Next day the same thing happens. And the third day too. Getting a little curious, the librarian follows the chicken on the fourth day, all across town to a swampy lake. At the lake he sees the chicken drops the book in front of a frog, who promptly says "Redit, redit."