A fourth-grade teacher is doing a science lesson and asks all the children to perform an experiment of their own choosing. After the children have been busy for a few minutes, she gets to the desk of little Johnny. Johnny has a spider on his desk and she asks what he is doing. …

“Well Miss, the spider’s name is Herbert and watch this.” Johnny then bends down to the spider and whispers “Run, Herbert, Run” and the spider, as if by magic, moves across the desk. The teacher is a little mystified. Johnny then gets a hold of the spider and removes one leg. The teacher is taken aback but lets the experiment continue. Johnny again whispers “Run, Herbert, Run” and the spider, as if by magic, moves across the desk. Johnny then gets a hold of the spider and removes another 2 legs and repeats the experiment. “Run, Herbert, Run” and the spider does continue to move across the desk, a in a somewhat limp fashion. By this time the teacher is getting a little concerned.
The experiment continues in the same vein until Herbert, the spider, has one leg left (the teacher at this point is totally mortified). Little Johnny then bends down to the spider and again removes the last leg so that Herbert is now just a blob and again he whispers “Run, Herbert, Run” but Herbert doesn’t move. He repeats the command again but a little bit louder. After several attemps, Johnny is now shouting at the spider “Run, Herbert, Run” but still no movement. Johnny then looks at the teacher and she asks “Well, Johnny, an interesting experiment, but what are you trying to prove with it?”
Little Johnny replies, “Well, Miss, spiders with no legs are deaf”