A duck walks into a store and asks the clerk if she has any grapes.

The clerk says no and the duck walks out of the store.

Five minutes later the duck walks back in and asks the same question.

The clerk says no again and the duck walks back out of the store.

Five minutes later the duck comes in again and asks the same question.

The clerk says, "No, I don't have any grapes and if you come in again and ask
the same question I'll nail your feet to the ground!" The duck walks out of the store.