How does an octopus know when to change it's color/set it's camouflage on?

They have been given brains to think, that’s how. Octopuses are one of the most intelligent animal species, and have even been shown to possess problem-solving skills.

Did you know that when Octopi are busy mating that they change colors spontaneously, going through the entire spectrum of colors like a rainbow?

As stated above, Octopi are one of the most intelligent critters in the world.

They know when they feel threatened and decide whether to spray ink, change colors/camouflage themselves, or to flee.
And they do this in the wink of an eye!

On the contrary, octopi have an extremely advanced nervous system compared to other invertebrates. Their brains are large and they form from a fusion of ganglia. Muscle contractions, sensory perception, memory and decision-making processes have a very large portion of the brain devoted to these processes. This allows the octopus to be a very smart animal that is able to learn and problem solve. Studies have found that an octopus can learn by watching other octopi, called observational learning. Not only are octopi smart animals they also have a very keen sense of sight. As a matter of fact their sight is somewhat like humans. One-way in particular their sight is better than ours is how the optic nerve is connected. The optic nerve is connected to the back of the retina in octopi, which allows the octopi to have no blind spots. Humans on the other hand have a blind spot because of the placement of the optic nerve. An octopus can make out shapes and some colors.

When feeding, octopi use their sense of sight to find their prey and their tentacles to catch the prey. The suction cups that line the tentacles are very sensitive to the touch. The tentacles have suction cups covering the bottom side of them, which allows them to grasp onto objects. Some of the suction cups may also contain protein. The protein helps to reinforce the suction cups, and small hooks help to aid in holding onto objects. Mastication is performed with a jaw and a radula. The jaws actually tear the food and the radula grasps the food and forces it into the mouth. Octopuses hunt for snails, fish, and crustaceans. They are nocturnal hunters. In some cases venom from salivary glands help to immobilize their prey so the may eat their prey more easily.

Chromatophores are cells that contain pigment. These cells give the octopus the ability to change color depending on the mood of the octopus. Chromatophores also help the animal blend in with its surroundings so that it may be camouflaged and harder to be found. This sometimes happens in correlation with a discharge of ink from the ink gland. The ink helps to allow the octopus to escape danger. The ink blinds their predator and it can help to disorient it long enough for a getaway. The ink can also be poisonous to other animals as well as itself if exposed long enough.

How do you know when to do all the things you do?
God gave you a brain, and you use it.

They don’t “know” when to change color any more than we “know” how to blush or how to contract their muscles than we know how to shiver in the cold. It is just physical reaction to external stimuli.

There is a great video that a naturalist just captured of an octopus dragging a shell across the ocean floor to use as a hiding place. They do definitely have some problem-solving ability but I agree the camoflage must be a physical reaction.

Actually, they do know when to change color. It is not merely a reaction. Is a well planned action.

Really? Cool!

I would guess (as in “I don’t know”) that it’s just instinctual. It just happens without them “choosing” to do it. Like what affects the behavior of most animals to mate.

@davidbetterman like when a kid reacts by holding his breath until he turns blue? lol

@galileogirl LOL…That never worked for me…

The same way everybody knows whether to fight or run away.

it decides.