Penguins do not fall over!
Everyone has read the story about penguins falling over backwards while observing low-flying aircraft. The Annals of Improbable Research reports that Dr. Richard Stone has been researching the ecological effects of helicopter overflights on King penguins and his preliminary results show that King penguins do not, in fact, fall over backwards (or forwards or even sideways) when you fly over them. On the other hand, low-flying aircraft do create distress among the penguins; Dr. Stone recommends a minimum overflight altitude of 1000 feet.
[Typo fixed, 24 September.]