American scientists have turned rats into "intelligent robots" by implanting electrodes in their brains. The remote-controlled rodents can be instructed to turn left or right, climb trees and navigate piles or rubble. Someday reserchers hope rats carrying tiny video cameras will be able to search for humans trapped under buildings in earthquakes and other disasters. The research was carried out by Sanjiv Talwar, a professor of physiology and pharmacology at the State University of New York in Brooklyn. "You essentially control the animal from afar. And that is a concern. If you're talking about larger animals they can carry larger payloads. And you can virtually strap anything else," said Talwar. Some scientists are concerned the technology could get into the hands of criminals or terrorists. The concept could be used to control humans. When given a signal by a laptop computer, the electrodes stimulated the rodents' brains and cued them to scurry in the desired direction. It then rewarded them by stimulating a pleasure centre in the brain.