A potato.
Mom: It's a private caller. Dad: Don't answer that. We only pick up for ranks Lieutenant Caller and higher.
Pupil: At night. Teacher: Why did you say that Pupil: Because my Dad always says that Rome wasn't built in a day!
Check their jeans.
Because a sheep can hear a zipper from a mile away.
Because he was a potato!
Potatoes don't scream when you peel their skin and toss them in boiling water.