Schooling

True schooling involves polarized, synchronized swimming with consistent spacing, distinct from shoaling (aggregation without coordinated movement). Schools are self-organizing — each fish responds only to its immediate neighbors using visual and lateral-line cues, yet the collective exhibits complex behaviors such as evasive flash expansion and vacuole formation that confuse predators. Predation dilution, the selfish herd effect, and confusion effects all contribute to schooling's anti-predator benefit. Hydrodynamic advantages from swimming in formation have also been documented in some species.