Dolphins have a social structure which makes them swim and live together in small groups called pods or herds. (Names of animal groups).
The best defense mechanism that dolphins have is their social organization and the strong bonds between them. The primary purpose of pods, composed of about 12 dolphins is the protection of the members.
These groups make sharks, the only predator that dolphins have to face, to avoid approaching the pod.
When threatened or attacked, dolphins use their speed and agility hit predators.