What Flies and Cries?

Okay, so you got a friend, right? And he's asking you a riddle: "What flies and cries?" Now, because you're a genius like my cousin who tried to mail himself to Florida, you'd never guess the answer is a cloud. Clouds float around in the sky, and when they're full of water, they "cry" by raining. Get it? Flies and cries? Cloud? I expected you to ask me to explain this one.