Ever wonder how a dolphin sleeps while still swimming? Or how a giraffe sleeps while standing up? Cara Santa Maria, Narrator of Smithsonian Earth's "The Secret World of Animal Sleep" joins Cheddar to explore the wild world of sleeping animals.

Marine mammals only shut down half their brain while sleeping, leaving the other half of their body to stay afloat and be alert for prey. She explains how the higher up on the food chain you are, the more sleep you get. That's why prey species like giraffes can only afford mere minutes of sleep at a time, while lions revel in over 20 hours of luxurious slumber a day.

Arctic ground squirrels survive harsh Canadian winters through skilled hibernation. Entering a state of controlled hypothermia, their body temperatures drop to 27°F – the lowest ever recorded in a mammal.