An atheist was seated next to a little girl on an airplane, turned to her and said, “Do you want to talk? Flights go quicker if you strike up a conversation with a fellow passenger.” 

The little girl, who had just started reading her book, replied to the total stranger, “What would you want to talk about?” 

“Oh, I don’t know,” said the atheist. “How about why there is no God?” as he smiled smugly. 

“OK,” she said. “That could be an interesting topic…but let me ask you a question first: a horse, a cow, and a deer all eat the same stuff- grass. Yet a deer excretes little pellets, while a cow turns out a flat patty, but a horse produces clumps. Why do you suppose that is?” 

The atheist, visibly surprised by her intelligence, thinks about it and says, “Hmmm, I have no idea.” 

To which the little girl replies, “Do you really feel qualified to discuss why there is no God when you don’t know shit?” And then she went back to reading her book.