At a Florida resort hotel, looking at a map:

Groucho:
Now here is a little peninsula, and here is a viaduct leading over to the mainland.
Chico:
Why a duck?
[more back-and-forth between the two ... ]

All right, why a duck? Why a duck, why-a no chicken?

Groucho:

Well, I don't know why-a no chicken. I'm a stranger here myself. ...