Your baby’s exhausted, but isn’t falling asleep. You’ve paced back and forth so many times that you’ve worn a hole in your sock, your shoe and the hardwood floor. Finally, after all that effort, you’ve gotten your little loved one to fall asleep in your arms. Ever so gingerly, you lean over the edge of the crib and lower her down on the mattress when – WHOA – out of nowhere, she flings her arms and legs out to the side and screams hysterically as if you’re tossing her into the Grand Canyon. Now she’s wide awake, kicking and yelling like never before, and you’re thinking, “What the heck did I do wrong?” (Actually, your dialogue is much more R-rated.)

The answer, my poor pathetic pooped-out parent, is that you did nothing wrong. You’re just dealing with one of the most horrific aspects of putting a baby to sleep: the Moro reflex (also known as the startle reflex). As you may know, babies are born with a veritable smorgasbord of fascinating and fun reflexes and responses. Stroke the sole of your baby’s foot and his toes flare out. Stroke her cheek, and she roots and turns her head to look for a nipple. Poke your finger into the palm of Baby’s hand, and he’ll grasp it and close his fingers around it like a sea anemone. You could play with these reflexes for hours. It’s like you’ve given birth to an eight-pound Game Boy.