Little Billy's father took his small son to the zoo. They were standing in front of the tiger's cage at the zoo. Billy's father was explaining how ferocious and strong tigers are, and little Billy was taking it all in with a serious expression.

"Dad," Billy said finally, "if the tiger got out of his cage and ate you up..."

"Yes, son?" Little Billy's father said expectantly.

Billy continued, "...what bus should I take home?"