Fish have a sensory organ called the lateral line which lies along the mid flanks of the fish. This organ is very sensitive and can pick up vibrations in the water, warning the fish of other species or predators in the water or on the bank. Using the lateral line organ, most fish can detect your footsteps on the bank from far away.

Other fish have weak electric organs to aid their navigation and to detect prey and predators. Fish have an acute sense of smell and can detect the smell of food and other substances underwater, sometimes at great distances.