A ducksAndFrog Joke

Two ducks go to a library and say : Buk Buk Buk.
The librarian- a pretty astute guy, thinks for a minute, then gives them three books.
The ducks leave.

The following day, the ducks return.
'Buk Buk Buuuuk'
-All right, all right, the librarian says. And he picks three other books for them.
The ducks leave.

They return the next day and say, with even more intensity : Buuuk Buuuuk Buuuuuuk!!!
The librarian chooses three other books but intrigued, decides this time to follow them.
They all walk slowly to a park. (Of course the ducks never rush...) Then they stop near a pond.

There, the librarian sees the ducks throw the books, one at a time, to a big frog standing like a powerful king, who dismisses them with a blasé "Rrrrredit, Rrrrredit, Rrrredit..."

NB: Rrrrredit= read it. Translated from frogs' language to English...