Noise Under Bed

All the fraternity brothers left the house for a long weekend except for Grady, who decided to stay behind and get some studying done.

One night Grady heard a noise under his bed.

Fearing it might be a burglar, he leaned over and whispered, "Anybody there?"

"No," said the burglar.

"That's funny," the boy said to himself. "I could have sworn I heard a noise!"