Tim, 11, could read the minds of the family's two cats. "I know when they're happy," he told his sister Ellen. "I know when they're sad. I know when they're hungry. I know when they're thirsty." Ellen, 9, said, "First of all, cats aren't happy or sad. They're not dogs. Dogs are happy or sad. Cats are just there! Second, you can't just look at a cat and know if it's hungry or thirsty. You only know it's hungry if you see it eating. You only know it's thirsty if you see it drinking." Tim said, "Oh, yeah? Watch this. The cats are hungry now. I can read their minds." He opened a can of cat food. Both cats heard the sound of the electric can opener. They came running. Tim put the food into their dishes. The cats started eating. Tim smirked at his sister. She rolled her eyes.