A Polish scientist was performing an experiment on the verbal reactions of fleas. He had trained a flea to jump on command.
The scientist commanded the flea, "Jump flea!" and the flea jumped four feet. The scientist wrote in his notebook: "Flea with four feet jumps four feet."
Then the scientist pulled off one of the fleas legs with a pair of tweezers and commanded the flea "Jump flea!" The flea jumped three feet and the scientist wrote it in his notebook.
The scientist did this until the flea had no legs left.
The scientist commanded, "Jump flea!"
He tried it again, "Jump flea!"
Again, nothing happened, so even louder he yelled, "Jump flea!"
And still the flea did nothing.
The scientist pulled out his notebook and wrote... "Flea with no legs is deaf!"