Remote controlled sharks

First of all these are not toys! For decades, the navy has used dolphins and sea lions to patrol harbors, salvage expensive hardware, and locate potential sea mines. Indeed, mounting chemical, auditory, or visual sensors on a shark is the easy part. In a project funded by the Defense Advanced Research Projects Agency (DARPA), Atema implanted sharks with electrical stimulators that trick their brains into smelling food. Using the stimulators, he was able to "steer" the sharks around a tank.