Son of Duck Joke

Wow. No flame mail over the original Duck Joke? Maybe I can get away with this one, too...

A duck goes into a bar. He hops up on a bar stool and says, "Got any duck food?"

The bartender says, "Of course not. This is a bar, not a feed store. Get lost." So the duck hops down and waddles out.

Next day, he's back: "Got any duck food?"
"No! Get out!"
Duck hops down and waddles out.

This goes on for a week. Finally, the bartender has had it.
"Got any duck food?"
"NO! And the next time you ask, I'm gonna nail your bill to the bar!"

Next day, incredibly, the duck is back: "Got any nails?"
"No."
"Great. Got any duck food?"