If you were to measure octopus smarts by the number of neurons the creatures have (500 million to our almost 100 billion), they’d come up pretty dull. But forget that metric. The octopus’s neurons aren’t even concentrated in its head; about two-thirds of its “brains” are distributed in its arms, dedicated to the fine operation of these limbs and each of their hundreds of suckers. The rest of the neurons are split between a central brain—surrounding the esophagus—and large optic lobes behind the eyes. Like we said: alien.