The Delphinidae family contains 36 species of dolphins, including killer whales. Dolphins travel in groups called pods and use echolocation to navigate the ocean. They communicate with one another using distinct whistles, clicks, grunts, moans and other sounds.
Dolphin nostrils are covered by a flap beneath the blowhole that opens and closes, allowing them to breathe above water. Depending on their species, dolphins eat fish, shrimp, squid, seals, penguins, octopus and other aquatic animals. Dolphins work as a team to herd and catch small animals. As the largest and fiercest species of dolphin, killer whales weigh up to 4.48 tons and grow as long as 23 feet.