A prominent scientist conducted a very important experiment. He trained a flea to jump upon giving it a verbal command (“Jump!”).
In the first stage of the experiment he removed the flea’s leg, told it to jump, and the flea jumped. So he wrote in his scientific notebook: “Upon removing one leg, all flea organs function properly.”
So, he removed the second leg, asked the flea to jump, it obeyed, so he wrote again: “Upon removing the second leg, all flea organs function properly.”
Then he removed the last leg, told the flea to jump, and nothing happened.
He did not want to take a chance, so he repeated the experiment several times, and the legless flea never jumped. So he wrote the conclusion: “Upon removing the last leg, the flea loses sense of hearing.”