He reminds his daughter that the family dogs and a neighbor's cats take frequent naps, and likens their pattern of alternating waking and sleeping to that of human babies and persons who are very old. She can see pets doing this, too, he notes, adding that twitching paws and whiskers also indicate dreaming sleep. Whales, she learns, must sleep with their heads sticking out of the water in order to breathe. Dolphins sleep with half of their brain part of the time, and then switch over to the other half, always moving. Even fish sleep.
Guppies have stripes along their bodies.
It's like the fish are changing from pajamas into clothes. Bats sleep upside down. Leopards sleep on tree limbs without falling. Penguins sleep standing up in circles with their backs to the wind, taking turns on the outside to permit those in the middle to sleep. Gentle water colors by Sari O'Sullivan show a wide array of dozing animals.