One of the great, simple joys of childhood is pouring a bowl of Kellogg’s Rice Krispies, dousing it with milk, and listening to the famous snap, crackle, and pop. Buy why, exactly, does the cereal make a noise when it gets wet?
According to Scientific American, it all comes down to the cooking process. Each grain of rice expands as it bakes in an oven, creating tiny air pockets inside (you can see the pockets and tunnels if you examine a Rice Krispie up close, but don’t let your co-workers see you doing it; here’s a magnified view). Once milk is added, the rice begins to absorb it, causing the walls of those pockets and tunnels to break, creating the signature sound.
Here’s another fun fact: not every language pronounces that iconic sound as “Snap, Crackle and Pop.” In German it’s “Knisper, Knasper, Knusper,” in Spanish it’s Pim, Pum, Pam,” in Swedish it’s “Piff, Paff, Puff,” and in Finnish it’s “Riks, Raks, Poks”!