Many marine experts believe that killer whales, a member of the dolphin family, are one of the most intelligent creatures on earth, MSNBC reports. While these animals cannot actually take an IQ test, some scientists measure their intelligence using the encephalization quotient (EQ). This essentially measures the size of an animal's brain compared to its body size to predict its cognitive abilities.

Using this scale, researchers have found that humans have an EQ of 7, while killer whales have an EQ of about 2.5, according to the news outlet.

Still, some professionals are not so sure that whales are more intelligent than humans. For example, the Macedonian International News Agency reports that researchers used comparative intelligence based on cortical structural development in the brain in order to test the cognitive skills of both mammals.

These scientists decided to assign humans a score of 100, which is the average adult result of an IQ test. Using this reference point, dogs would earn a score of about 15, while chimpanzees would receive a 35. However, based on cortical structure comparisons, sperm whales would earn a 2,000, which, theoretically, would make them much smarter than humans.