To learn more about how animals communicate, researchers are developing robotic copies capable of signaling real-world creatures, then analyzing how the non-battery-powered respond. Most recently, Hampshire College researcher Sarah Partan, for example, has been working with a mechanical squirrel she calls Rocky.

At 1,200 pounds and 14 feet long, "Troy" is chunkier than the average great white shark. He might smell kind of funny too. But do the pods of sharp-toothed predators he swam among last winter know that, inside, there's just a man? Or that it was Fabien Cousteau, grandson of pioneering undersea explorer Jacques, surreptitiously recording their every movement?