Hector dolphins use echolation to find food. they send high frequency clicks that bounce off surrounding objects and fish giving the dolphins a detailed picture and information on how fast the object/fish is moving. (to locate prey) They swim in pairs or groups up to 12.
Not with the naked human eye. The eye needs at least a little light in order to be able to see. With special equipment, we can measure things like infrared heat and "see" even if there is no light, but that's not really seeing because you're using machines instead of your eye.
they let a high pitched sound out of their mouth and it echo's back if it's hit's something if not it keep moving until i does Many types of bats as well as aquatic mammals such as whales and dolphins regularly use echo-location to find food and find their bearings.
It seems there may be a spelling error in your question. If you are referring to "echolocation," it is a technique used by animals, such as dolphins and bats, to navigate and locate objects by emitting sound waves and listening to the echoes that return. This allows them to understand their surroundings, locate prey, or avoid obstacles.