Behold! Sleeping whales! I had no idea. It must be a strange sight to come upon a pod of sleeping whales. I wonder what they dream about. I also learned that birds can shut off half their brains when they sleep, keeping the other half alert to watch for predators. In one experiment, researchers put all their ducks in a row, literally. The ducks in the middle slept with both eyes closed. But the first and last ducks each kept their outer eye open while they slept. I kind of wish I could do that!