This is the way had it from my mother (who was in the Guides pre-war):

There was once a rabbit
Developed the habit,
Of twitching the end of his nose.
His sisters and brothers
And various others
Said, "Look at the way that it goes".

Now one little bunny
Said, "That's very funny,
I'll practise it down in the dell".
They allrest said, "If he can,
Then certainly we can".
And did it remarkably well.

Now all the world over,
Where rabbits eat clover,
And scrabble and scratch with their toes,
There isn't a rabbit,
Who hasn't the habit,
Of twitching the end of its nose.