Why Do Octopuses Haul Coconut Shells Like Portable Armor? The Surprising Science Behind Their Unusual Tool Use

Octopuses are already known for being highly intelligent creatures. They have been observed in various settings solving problems and escaping from containers. They are also known for having good memory and the ability to spot patterns in the environment. However, there was a recent discovery in the waters of Indonesia involving octopuses that surprised even the most experienced marine biologists.

The species in this discovery is called the veined octopus. They are known for collecting coconut shells and using them as a shelter when they are in danger.

The behavior of the octopus at first seems funny. They collect coconut shells and carry them under their bodies as they move through the sand. They then use the shells as a shelter when they are in danger. The two halves of the coconut shell are arranged in such a way that they create a small dome when placed together.


What makes this behavior so interesting is not the object the octopus is using, but the fact that the octopus is using the object before they are in danger.

A Discovery That Changed How Scientists Think About Octopus Intelligence

The behavior was carefully recorded in 2009 by marine researchers Julian Finn, Mark Norman, and Josh Tregenza. Their findings were published in the journal Current Biology in a study describing how the veined octopus, Amphioctopus marginatus, uses tools.

While watching near Sulawesi, Indonesia, the researchers saw several octopuses pick up coconut shells from the ocean floor. The animals then carried the shells across open sand, sometimes for several meters, before finally using them as a shelter.

Because the shells were picked up and carried before they were needed, the scientists decided this counted as using a tool. The octopus was choosing something and saving it for later protection.

Reports on the discovery later highlighted another unusual detail. According to National Geographic, the octopus often walked in an awkward, stilt-like posture while balancing the shells underneath its body. This slowed the animal down and made it more visible to predators.

That risk suggests the octopus is making a tradeoff. It accepts a temporary disadvantage so that it can have a ready-made shelter when a predator appears.

Researchers say this wait between picking up the object and using it suggests a kind of planning. Instead of hiding right away, the octopus gets ready for something that has not happened yet.

A Portable Shelter in an Open Landscape

Scientists sometimes call the coconut shells portable armor. When danger comes, the octopus pulls the two halves together and hides under them.

This strategy works especially well in sandy parts of the ocean floor where there are not many natural shelters. Reports from Live Science say that these open areas often do not have rocks or coral where an animal could quickly hide. Carrying a shelter solves that problem.

This behavior is also different from what other animals that use shells do. Hermit crabs rely on shells as permanent homes. The veined octopus uses coconut shells in another way. It carries them when needed and leaves them behind once the danger is gone.

Watching octopuses in the wild has even shown that some return to shells they used before, which suggests they may remember where useful things are in their surroundings.

A Small Behavior with Big Implications

The coconut shell strategy is now regarded as one of the most obvious examples of tool use in animals without a backbone. The Guardian and subsequent studies of tool use in animals highlighted just how unusual this discovery was.

Octopuses have a very different nervous system from that of mammals or birds. Many of their nerve cells are actually in their arms, rather than in their brain. Yet despite these differences, octopuses are capable of remarkable abilities when it comes to solving problems.

To scientists who seek to understand how animals think, the veined octopus is an important reminder that intelligence does not increase in just one way or in just one group of animals.

Sometimes it seems to turn up in unexpected places, such as on the quiet seabed where a small octopus works its way across the sand carrying a coconut shell in preparation for some threat that may come later.