“Sounds of Silence” — The Discovery Files

If you want to hear rare Chinese frogs croak, speaking the language won’t necessarily help. These frogs can make high-pitched sounds out of human hearing range. Biologists at the University of Illinois have found a particular frog species that has the same ultrasonic communication ability as bats, whales and dolphins. And there may be good reason why Nature has given these critters their own “Frogs ‘N Family” plan.