This comment is in a dire need of citation. Let me provide it: Why We Sleep: Unlocking the Power of Sleep and Dreams by Matthew Walker. The book states that ev

This comment is in a dire need of citation. Let me provide it: Why We Sleep: Unlocking the Power of Sleep and Dreams by Matthew Walker. The book states that every living organism on earth so far tested has shown signs of sleep or sleep like behaviour (like not moving for periods of time, relaxed state, etc).