“Let’s go get Grandpa,” Burt said. “He knows everything!” The two boys ran back to the clearing where their grandfather was sitting on a bench waiting for them.

Nearly out of breath, they ran up to him. “Grandpa, you’ve got to come see what we found,” Ernie said. They each grabbed a hand and led him back to what had gotten them so excited.

“Ernie says that it’s man-made,” Burt said, “but I think it’s natural. Who’s right?”

The old man examined the large hole in the rock formation. “Neither of you,” he said. “This was made by the mole people.”