Do octopuses have nine brains?
An octopus has nine brains that control its body and eight arms.
A central brain handles big decisions and memory. Each arm has its own mini-brain that lets it move, touch, and taste things on its own. This allows the arms to hunt or explore without waiting for orders from the head.
Nerd's Section
An octopus has about 500 million nerve cells. This is roughly the same number of neurons found in a dog. Two-thirds of these nerve cells are located in the arms rather than the head. Researchers like Dr. Jennifer Mather found that octopus arms can still react to touch even if they are separated from the body.The central brain acts as the main control center for high-level tasks. The clusters of nerve cells at the base of each arm handle complex movements. Each arm contains sensors that allow it to taste and feel its surroundings. This setup saves time because signals do not have to travel all the way to the head and back.Studies in the journal Current Biology show that arms can perform tasks like opening jars with little help from the main brain. The arms use reflex loops to react instantly to food or danger. This trait evolved over 300 million years ago after octopuses lost their heavy shells. They needed a faster way to move and hide to stay safe. This system is so fast that an octopus can change its skin color in less than one second.
Verified Fact
FP-0002289 · Mar 16, 2026