So he bent down, put his head into the hole, and called out:
"Is anybody at home?"
There was a sudden scuffling noise from inside the hole, and then silence.
"What I said was, 'Is anybody at home?'" called out Pooh very loudly.
"No!" said a voice; and then added, "You needn't shout so loud. I heard you quite well the first time."
"Bother!" said Pooh. "Isn't there anybody here at all?"
"Nobody."
Winnie-the-Pooh took his head out of the hole, and thought for a little, and he thought to himself, "There must be somebody there, because somebody must have said 'Nobody,'" So he put his head back in the hole, and said:
"Hallo, Rabbit, isn't that you?"
No," said Rabbit, in a different sort of voice this time.
"But isn't that Rabbit's voice?"
"I don't think so," said Rabbit, "It isn't meant to be."
Taken from "In which Pooh goes Visiting and gets into a Tight Place"