The Soul of an Octopus: A Surprising Exploration into the Wonder of Consciousness

by Sy Montgomery

But other changes certainly reflect mood. Nobody has figured out what all the color changes mean. A few are known: A giant Pacific octopus who turns red is generally excited; a white one is relaxed. An octopus presented with a difficult puzzle for the first time often undergoes several rapid changes in color, like a person who frowns, bites his lip, and furrows his brow when trying to solve a problem. A nervous octopus takes special care to disguise its head and especially its eyes, and can create a variety of spots, bars, and squiggles to confuse a predator. The small, deadly poisonous, blue ring octopus of Australia flashes dozens of electric-blue namesake rings all over its body when threatened. Another disguise is known as the eyebar display, in which an octopus makes a thick, dark line extend at the outer edge of the eye from either end of each slit pupil, masking the roundness that is typical of an eye.