Are caterpillars good to eat?
Johnny: Daddy, are caterpillars good to eat?

Father: Have I not told you never to mention such things during meals!

Mother: Why did you say that, Junior? Why did you ask the question?

Johnny: It's because I saw one on daddy's lettuce, but now it's gone.

After surgery
As the lawyer slowly came out of the anesthesia after surgery, he said, "Why are all the blinds drawn, doctor?"

"There's a big fire across the street," the doctor replied. "We didn't want you to think the operation was a failure."