You can usually find the great barracuda swimming near the surface of the water. Adults usually swim alone, especially at night, but at other times you can find both young and adult barracuda swimming in schools. A school is when many fish swim together. Sometimes hundreds or even thousands of barracuda will swim together, but this is rare. Barracuda attack almost anything, even if they eat only a little of it. They have been known to attack humans and cause serious injuries, but only if we bother them.