A young college student had stayed up all night studying for his zoology test the next day. As he entered the classroom, he saw ten stands with ten birds on them. Each bird had a sack over its head; only the legs were showing. He sat straight in the front row because he wanted to do the best job possible. The professor announced that the test would be to look at each of the birds' legs and give the common name, habitat, genus and species.
The student looked at each of the birds' legs. They all looked the same to him. He began to get upset. He had stayed up all night studying and now had to identify birds by their legs. The more he thought about it the madder he got.
Finally he could stand it no longer. He went up to the professor's desk and said, “What a stupid test! How could anyone tell the difference between birds by looking at their legs?” With that the student threw his test on the professor's desk and walked to the door.
The professor was surprised. The class was so big that he didn't know every student's name so as the student reached the door the professor called, “Mister, what's your name?”
The enraged student pulled up his pant legs and said, “You tell me buddy! You tell me!”