But as Piero Amodio, an animal behavior and cognition researcher in Napoli featured in “Octopus!” says in the series, the idea of intelligence is a human one.

The team discovered that the Pygmy zebra octopus has stripe patterns as unique as human fingerprints, allowing even humans to tell them apart.

National Geographic releases a new docuseries, "Secrets of the Octopus," revealing that the creatures are more human-like than we think.

The reddish giant Pacific octopus wrapped its tentacles around the diver and his camera, as if clicking a selfie with him.