I'm about the size of your fist, and I beat all day and all night, even while you sleep. What am I?
Show hint
Run fast, then put your hand on your chest. You'll feel me thumping.
Show answer
Your heartYour heart is a muscle about the size of your fist. It beats around 100,000 times a day, pumping blood around your body even while you sleep.
About this riddle
A science riddle about something inside you that never takes a break. After a run, put your hand on your chest to check your guess.
It comes from Human Body Riddles, a collection of 30 riddles with hints and answers, sorted from easy to tricky. Play the video, pause it when the riddle ends, and see if you can solve it before the answer appears.
