How do fish move as a school? Fish have what’s called a lateral line - a vital sensory organ that runs from their gills to their tail. This “sixth sense” allows fish to detect movement and pressure changes in the water column. Which ultimately enables them to move as one without actually seeing what they’re swimming from! Not only does this sensory organ help fish hunt and avoid predators it also helps them, in this case navigate in low visibility. Next time you see fish moving as ONE being, wel