Orcas, or killer whales, are the largest of the dolphins and one of the world's most powerful predators. They feast on marine mammals such as seals, sea lions, and even whales, employing teeth that can be four inches (ten centimeters) long. They are known to grab seals right off the ice. They also eat fish, squid, and seabirds. Though they often frequent cold, coastal waters, orcas can be found from the polar regions to the Equator. The average life span in the wild is 50 to 80 years and they weigh up to 6 tons (5,443 kg)