One day a man claims himself to a scientist in on his research. He took a cockroach and cut one of its legs and said jump. The cockroach hopped. He removed it's second and said jump.. The cockraoch hopped . Removed it's third leg and said jump. It hopped lightly. He removed all it's leg and said jump.. The cockroach couldn't jump..
Concluded his thesis.. Cockroach donot hear when it looses all its legs.