The answer to the riddle "what runs but never walks" is a river. This riddle appears in multiple sources. The answer is a play on words, as a river is said to "run" or flow, but it does not actually walk. Additionally, a river has a "mouth" where it meets the ocean or another body of water, but it does not talk. It also has a "head" or source, but it does not weep. Finally, a river has a "bed" or channel, but it does not sleep.