Which animal is the smartest after humans?

There is no single smartest animal, because intelligence takes many forms, but several species consistently astonish researchers. Great apes, especially chimpanzees and bonobos, share about 98 to 99 percent of human DNA and can use tools, learn sign language, and solve complex problems. Dolphins have large, sophisticated brains, use signature whistles like names, and cooperate in clever hunting strategies. Elephants show remarkable memory, empathy, and self-awareness. Among birds, crows and ravens craft and use tools and plan ahead, while parrots can learn to use words meaningfully. Octopuses display surprising problem-solving despite being invertebrates. Rather than ranking them, scientists study how each animal intelligence is adapted to its way of life, revealing that clever minds evolved independently many times.