Suppose a school of fishes suddenly turns. Who initated this turn? Was this “leader” responding to a stimulus? Was he acting first because of the topology of the swarm, him being closest to the cue? Or do individuals exist with a higher probability of leading? What properties do leaders have? Is it their looks, or their behavior that make the others follow?
Using a biomimetic fish robot we are able to test various hypotheses: we can make the Robofish thin or big, act risk-averse or adventurous, nervous or calm. Having full control over the hypothesis, experiments are perfectly reproduceable.