You know that annoying moment when you suddenly wake up in the middle of the night and can't get back to sleep? The reason we do this goes way back to our caveman days when we needed to check the safety of our surroundings even at night. But not being able to fall right back asleep after these nighttime interruptions is actually a bad sign. So what’s keeping you awake? Stay tuned to find out! Learn more about your ad choices. Visit megaphone.fm/adchoices