Saltpetersyra

A chicken walks into the library. It goes up to the circulation desk and says: "book,bok, bok, boook". 
The librarian hands the chicken a book. It tucks it under his wing and runs out. A while later, the chicken runs back in, throws the first book into the return bin and goes back to the librarian saying: "book, bok, bok, bok, boook". Again the librarian gives it a book, and the chicken runs out. The librarian shakes her head. 
Within a few minutes, the chicken is back, returns the book and starts all over again: "boook, book, bok bok boook". The librarian gives him yet a third book, but this time as the chicken is running out the door, she follows it. 
The chicken runs down the street, through the park and down to the riverbank. There, sitting on a lily pad is a big, green frog. The chicken holds up the book and shows it to the frog, saying: "Book, bok, bok, boook". The frog blinks, and croaks: "read-it, read-it, read-it".