A party of young men were camping, and to avert annoying questions they made it a rule that the one who asked a question that he could not answer himself had to do the cooking.
One evening, while sitting around the fire, one of the boys asked: "Why is it that a ground-squirrel never leaves any dirt at the mouth of its burrow?"
They all guessed and missed. So he was asked to answer it himself.
"Why," he said, "because it always begins to dig at the other end of the hole."
"But," one asked, "how does it get to the other end of the hole?"