Shoaling and schooling
Confusion effect – One potential method by which fish schools may thwart predators is the ‘predator confusion effect’ proposed and demonstrated by Milinksi and Heller (1978). It becomes difficult for predators to pick out individual prey from groups: the moving targets create an overload of the predator's brain. "Shoaling fish are the same size and silvery, so it is difficult for a visually oriented predator to pick an individual out of a mass of twisting, flashing fish and then have enough time to grab its prey before it disappears into the shoal".