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A Newfound 'Octopus City' Resurfaces Old Questions About the Animal's Social Intelligence

Scientists were surprised to find that this smart and solitary species had built a cephalopod city. But why?
A young octopus on display.

Despite his name, Squidward Q. Tentacles—the grouchy neighbor of SpongeBob SquarePants in Nickelodeon's long-running cartoon—isn't a squid. He's an octopus. (Allegedly, creator Stephen Hillenburg named him Squidward because "Octoward" sounded too weird.) On the show, Squidward lives inside a moai head at 122 Conch Street, next door to SpongeBob's pineapple, in the underwater city of Bikini Bottom.

A sarcastic loner, he tries to avoid the relentlessly chipper sponge and his other neighbor, the slow-witted starfish Patrick, by staying in, drinking tea, and practicing the clarinet. You know what they say: An octopus' moai is his castle.

Hillenburg, as many of the show's fans know, used to be a marine biologist, and it turns out that Squidward's domestic bent is shared by octopuses in the real world. The species has long been known to collect bits and pieces from the sea floor to make "gardens" (thanks, Ringo) or build themselves personal dens. But now comes evidence that Tentacle Acres—the cephalopod-only community that Squidward briefly moves to in season two of SpongeBob—is not just a fiction.

In Quartz, Ephrat Livni writes that researchers have identified a community of 15 octopuses living together in Jervis Bay, off eastern Australia. The discovery was surprising because members of this species, the Sydney or gloomy octopus, were thought to be loners. Instead, the researchers observed them "congregating, communicating, dwelling together, and even evicting each other from dens" at the cephalo-city, which the scientists dubbed Octlantis. This is the second such octopus conclave found near eastern Australia in recent years. The first, Octopolis, was discovered in 2009, and was considered an anomaly at first.

Octopolis and Octlantis both sit on rock outcroppings on otherwise flat, nondescript areas of the sea floor. Lead researcher David Scheel of Alaska Pacific University speculates that topography might have something to do with the octopuses' turn toward urbanism. "Congregations such as these probably occur wherever shelter is limited to small patches of habitat, and food is plentiful," he told Quartz. (If food were less plentiful, presumably they'd be fighting each other too much to live together for any period of time.)

The octopuses didn't just drift toward the same secure-looking outcroppings, though. Once there, they built piles out of shells from scallops, clams, and other animals they ate, then sculpted the piles into dens, "making these octopuses true environmental engineers," as another of the researchers, Stephanie Chancellor, has noted. The creatures were about as patient with each other as Squidward is with SpongeBob on a bad day at the Krusty Krab, starting fights and chasing each other out of the dens—a phenomenon the research team doesn't quite understand yet.

Octopuses are far from the only non-human animals to engage in architecture and city-building. A beehive may hold tens of thousands of bees, and they build its structure—the honeycomb—out of wax that worker bees secrete, which is then formed into six-sided cells for maximum compactness and labor efficiency. Tiny termites can construct earth-and-fungus mounds as tall as a two-story house. And fire ants climb on top of each other to build towers out of their own bodies.

Octopuses aren't part of a super-organism, as those insects are. They're still mainly solitary creatures. But the complex social interactions required to establish a village lend support to the theory that they are much, much smarter than we had ever suspected.

In 2009, researchers observed veined octopuses collecting coconut-shell halves, schlepping them around, and later assembling them into a protective armor—essentially, using them as tools. In zoos and aquariums, octopuses are notorious escape artists who may start disassembling their tanks when no one's looking. They have distinct personalities and form strong opinions about the humans they meet, and not always good ones: One octopus at the New England Aquarium sprayed a jet of water at the same volunteer every time she visited him.

For humans, it's hard to conceptualize a kind of intelligence in which the head plays a secondary role: What would it be like to think with your arms?

What makes the octopus so extraordinary is its nervous system. Most of its neurons are in the tentacles. For humans, it's hard to conceptualize a kind of intelligence in which the head plays a secondary role: What would it be like to think with your arms? Recent research also suggests that octopuses may be able to see with their skin, which enables their color-changing mimicry of other animals.

There is still a lot scientists don't know about why octopuses create these mini-cities and what they do there. But the idea of a city that might be navigated with limbs and skin is tantalizing—and not so different, in fact, from the field of tactile design, which seeks "to engage the whole person and not just the eyeballs," as proponent Ellen Lupton has said. (A good example of tactile design is a multi-sensory crosswalk with textured paving.)

Neuroscience reveals that humans experience urban places through the movement of our bodies as much as our conscious thoughts. And biomimetic architecture applies time-tested principles from the natural world to human design problems. A building in Harare, Zimbabwe, employs a cooling system based on the engineering of a termite mound. Why not an octopus-inspired building, or city, one day?

One thing that's very clear about octopuses: They have a strong instinct for self-protection. Their coconut-shell armor and stony dens are ways to fend off predators. As they evolved, octopuses lost their own shells, which freed their bodies to move more, but also left them more exposed.

To go through life in a soft, vulnerable body and evade danger by your wits: That is something we humans can relate to. Safety and collective self-defense are the main reasons our species chose to overcome our suspicions of each other and gather together to live in cities in the first place, after all. Maybe that's why we're fascinated by these ink-squirting, city-building, marvels of the deep.

This story originally appeared on CityLab, an editorial partner site. Subscribe to CityLab's newsletters and follow CityLab on Facebook and Twitter.