What does a fish look for in a leader? No doubt a nice fishy smell is important, and maybe a sense of direction too, but the overriding factor happens to be something much simpler, and indeed simple enough for a robot to mimic. Our old friend Maurizio Porfiri and a colleague from New York's Polytechnic Institute have shown that a fish-bot will quickly attract live followers if it has a nice, fluid swimming motion. When the stroke is just right, real fish will pull up alongside an
