Robot fish, tiger dropping microphone among gadgets on display

McLEAN, Va. - When the CIA’s secret gadget-makers invented a listening device for the Asian jungles, they disguised it so the enemy wouldn’t pick it up and examine it: The device looked like tiger droppings.

The clever guise worked. Who would touch such a thing? The fist-sized, brown transmitter detected troop movements along the trails during fighting in Vietnam, another quiet success for a little-known group of agency researchers.