And the stones themselves shall rise up against you
New U.S. Army sensors rock - (United Press International)
: "Washington, DC, May. 27 (UPI) -- The U.S. military is developing miniature electronic sensors disguised as rocks.
The disguised sensors can be dropped from an aircraft and used to help detect the sound of approaching enemy combatants, the London Financial Times has reported.
The devices, which would be no larger than a golf ball, could be ready for use in about 18 months, the paper said. They use tiny silicon chips and radio frequency identification, or RFID, technology that is so sensitive that it can detect the sound of a human footfall at 20 feet to 30 feet. RFID technology uses radio signals that are sent from a silicon chip to a remote sensing device."