Strange Slumber

S1, E6: Strange Slumber

Available on Smithsonian Channel, Prime Video, Hulu
All animals sleep--but few do so in exactly the same way. Horses snooze standing up, and snakes sleep with their eyes wide open. As for some species of jellyfish, they sleep despite lacking a brain! Uncover some of the more unusual features of animal slumber, many of which remain a mystery to us.