Octopus ink doesn’t just hide the animal. The ink also physically harms enemies. It contains a compound called tyrosinase, which, in humans, helps to control the production of the natural pigment melanin. But when sprayed in a predator’s eyes, tyrosinase causes a blinding irritation. It also garbles creatures’ sense of smell and taste. The defensive concoction is so potent, in fact, that octopuses that do not escape their own ink cloud can die.