How Octopuses Solve Puzzles

An octopus does not have a single brain. It has nine. There is one central brain, between its eyes, which handles big decisions. And there is a smaller brain in each of its eight arms, which can think — and act — almost independently. This means that, in any given moment, an octopus may be solving up to nine separate problems at once.

In aquariums around the world, scientists love to set octopuses puzzles. A favourite is the jar puzzle. A scientist puts a tasty crab into a glass jar, screws the lid on tight, and lowers the jar into the tank. The octopus, which has never seen a jar in its life, must work out how to open it.

Most octopuses take only a few minutes. Some have been filmed taking just thirty seconds. They explore the jar with their arms, find the lid, and unscrew it — anti-clockwise, like a human — until the crab is theirs. What is most remarkable is that, when the same octopus is shown the jar a second time, it solves it even faster. The memory has been stored — not in the central brain alone, but possibly in the arms themselves.

Octopuses are also great escape artists. There are countless stories of pet octopuses opening tank lids at night, slithering across the floor, eating fish from a neighbouring tank, and slithering back to bed before morning. They have been observed using rocks as shields, coconut shells as armour, and — once, famously — a row of glass jars as stepping stones to freedom.

For animals with no bones, no faces, and almost nothing in common with us, octopuses are surprisingly good at being clever in our world.