Have you ever wondered how fish in a school synchronize their movements perfectly while swimming?
According to the April-May 2016 issue of the Nature Conservancy Magazine (page 12), a 2013 study from biologist Iain Couzin’s labs at Princeton University and the Max Planck Institutes in Germany shows that schooling fish respond quickly to movements of other fish within their eyesight. Earlier, they found that if they trained only five percent of a school of fish to move toward a light for food, the rest would follow. Also, when fish on the edge of a school shy away from hazards, they steer the entire group away. But the group need to be large enough. So if schools become smaller due to, say, overfishing, each fish is less likely to avoid danger. Another interesting finding is the mechanics of collective fish movement have been seen in other ways, like the spread of ideas through a society or the behavior of cancer cells.
Another viewpoint is fish swim like we drive. They follow simple rules, like us on the freeway, which could offer some lessons for designing self-driving cars. The implication is that fish in large schools make better decisions than individual fish or small schools. You can find this explained at http://www.globalanimal.org/2011/11/09/less-traffic-jams-for-fish-under-water-video/
You can learn something from just about anyone, even fish!