Awake or Asleep?
Gray whales will swim 24/7, en route to Mexico's Baja Peninsula. What about sleeping? Scientists discovered that a gray whale can rest or sleep while it swims slowly or while it lies very still on the surface of the water. It might have both eyes open, both eyes closed, OR one eye open and one eye closed! Scientists think a whale can shut down half its brain. The other half stays alert enough to come up to take a breath, or to notice trouble. Do you think this whale is awake or asleep?

Gray whale up close, with eye open

Image: Keith Jones, Baja Jones Adventure Travel