Our bodies do a lot of weird things, and many of them are completely involuntary. Why do we often jerk our bodies awake right before falling asleep? Why do we yawn? Why do we hiccup? Why do some people sneeze when they look at the sun? And why does your eye twitch? This week we'll look at the science behind these crazy involuntary behaviors!

Originally released by Knowledgemotion, 2016. Streaming video file encoded with permission for digital streaming by Infobase on February 21, 2020.