They had come to a stream which twisted and tumbled between high rocky banks, and Christopher Robin saw at once how dangerous it was.
"It's just the place," he explained, "for an Ambush."
"What sort of bush?" whispered Pooh to Piglet. "A gorse-bush?"
"My dear Pooh," said Owl in his superior way, "don't you know what an Ambush is?"
"Owl," said Piglet, looking round at him severly, "Pooh's whisper was a perfectly private whisper, and there was no need--"
"An Ambush," said Owl, "is a sort of Surprise,"
"So is a gorse-bush sometimes," said Pooh.
"An Ambush, as I was about to explain to Pooh," said Piglet, "is a sort of Surprise."
"If people jump out at you suddenly, that's an Ambush," said Owl.
"It's an Ambush, Pooh, when people jump at you suddenly," explained Piglet.
Pooh, who now knew what an Ambush was, said that a gorse-bush had sprung at him suddenly one day when he fell off a tree, and he had taken six days to get all the prickles out of himself.
"We are not talking about gorse-bushes," said Owl a little crossly.
"I am," said Pooh.
Taken from A.A. Milne's Winnie-the-Pooh, "Expotition to the North Pole".