 Commonly used dither fish are typical schooling species, such as some "Danio", barb and tetra species, and are most often used in cichlid tanks.Dither fish are typically fish that swim around the top of a tank, a behavior that reassures more timid fish that no predators are nearby, and are found naturally in the same habitat as the other fish in the aquarium, thereby encouraging them to relax and engage in normal behaviour.This technique relies on the ability of cichlids in an aquarium to gauge environmental security by observing the behaviour of other fish species.