Joke: Spiders listen to sounds with their feet _ Laugh till their stomachaches _ Laugh till their girlfriends are happy.

A student was listening to the teacher's lecture when a spider landed on his desk and caught the students' attention. He found that spiders have eight feet instead of ears. So he suspects that spiders listen to sounds with their feet. The student ran to ask the teacher, and the teacher said, "You might as well do an experiment or have a look." So the students did it.

Name of the experiment: "Do spiders listen to sounds with their feet?"

Experimental tools: a table, a knife and a spider.

Experiment 1: Put the spider on the table and shout "Climb". The spider crawls forward.

Experiment 2: Cut off the spider's feet with a knife, put them on the table and shout "climb", but the spider doesn't climb.

Experimental conclusion: Spiders listen to sounds with their feet.