Why octopus?
No guilt trips. No graphic photos. Just what scientists have learned about one of the most extraordinary animals on Earth.
8 reasons in 88 seconds ↓
Photo by Diego Delso, delso.photo, CC BY-SA 4.0
Fast facts
Bucky fact checkYes, octopuses really can do all of this. I checked the sources. One per arm.
Giant Pacific octopuses treated a person who fed them differently from a person who poked them with a bristly stick, even when both wore identical uniforms. They remember how you treated them.
Bucky says We remember who's nice. Just saying.
Source Anderson et al., 2010(opens in a new tab)Octopuses learned to avoid a place where they had been hurt and to prefer one where they were given pain relief. Researchers say this suggests pain they actually feel, not just a reflex.
Bucky says It hurts us too.
Source Crook, 2021(opens in a new tab)Source Birch et al., 2021(opens in a new tab)An octopus mother guards her eggs until they hatch, eating little or nothing, and most mothers die after that one brood. One deep-sea mother was watched guarding hers for 53 months, the longest brooding period known for any animal.
Bucky says Call your mom.
Source Robison et al., 2014(opens in a new tab)Researchers who watched octopuses over time found clear, lasting differences between individuals. Some were bold, some shy, some always busy. Every octopus has a personality of its own.
Bucky says I'm the charming one.
Source Mather et al., 1993(opens in a new tab)Octopuses have been seen jetting water at a floating bottle again and again, pushing it around their tank and catching it on the return. It meets the scientific criteria for play.
Bucky says Work hard, play harder.
Source Mather et al., 1999(opens in a new tab)Source Kuba et al., 2006(opens in a new tab)When octopuses sleep, they slip into an active stage where their skin flickers through the same patterns they show when awake, and their brain activity looks like waking. Scientists have compared it to REM sleep, when people dream.
Bucky says Last night I dreamt about a really good rock.
Source Pophale et al., 2023(opens in a new tab)Source Medeiros et al., 2021(opens in a new tab)In lab studies, octopuses have learned to open closed jars to reach food inside, getting faster with practice, and to work out how to pull a puzzle box through a small opening.
Bucky says Childproof? Sure. Octopus-proof? Debatable.
Source Fiorito et al., 1990(opens in a new tab)Source Richter et al., 2016(opens in a new tab)Veined octopuses gather discarded coconut shell halves, carry them across the seafloor, and assemble them into a shelter when they need one.
Bucky says Packing for a trip, octopus-style.
Source Finn et al., 2009(opens in a new tab)Eight reasons. One small decision.
Think you remember them all? Take the quiz →How smart, compared to what?
So you won't see us claim an octopus is smarter than your dog. Here's how they actually measure up.
An octopus has about 500 million neurons. That's roughly as many as a dog has in its cerebral cortex, the part of the brain most linked to thinking, and about twice as many as a cat's.
Source Hochner, 2012(opens in a new tab)Source Jardim-Messeder et al., 2017(opens in a new tab)In a major 2020 review, Cambridge researchers found that octopuses and their relatives have perception, learning and memory abilities comparable to some vertebrates.
Source Schnell et al., 2020(opens in a new tab)Scientists gave cuttlefish, close relatives of octopuses, a version of the famous marshmallow test first designed for children. They held out up to two minutes for a better snack, the kind of self-control seen in chimpanzees, crows and parrots.
Source Schnell et al., 2021(opens in a new tab)Source Schnell et al., 2023(opens in a new tab)Compare
Octopus
500 million
neurons in its whole nervous system
In the brain (about a third) In the arms (about two-thirds)
Source Hochner, 2012(opens in a new tab)Dog
1.8 to 2.6 billion
neurons in the whole brain
In the cerebral cortex: 429 to 627 million Rest of the brain
Source Jardim-Messeder et al., 2017(opens in a new tab)A dog's brain has about four times as many neurons in total. But its cerebral cortex, the part most linked to thinking, holds 430 to 630 million. That's about the same as an octopus's entire nervous system.
Dogs
Dogs can follow a person's pointing gesture to find hidden food.
Source Hare et al., 2002(opens in a new tab)Octopuses
Octopuses can tell individual people apart, even when they wear identical uniforms.
Source Anderson et al., 2010(opens in a new tab)Each dot is 10 million neurons. Counts come from published studies of individual animals and vary from one individual to the next. The octopus figure covers its whole nervous system; for other animals it's the whole brain. Neuron counts are a useful way to compare brains, but on their own they aren't a measure of intelligence.
Go deeper
Octopus intelligence evolved along a completely separate path from ours. An octopus has roughly 500 million neurons, and about two-thirds of them are in its arms, not its brain. Each arm can explore, grasp and react with a surprising degree of independence, while the central brain coordinates the whole animal.
Source Hochner, 2012(opens in a new tab)Octopuses learn quickly and remember what they learn, including where safe burrows are hidden. In a classic, and still debated, 1992 study, octopuses that watched another octopus choose a particular object later tended to choose the same one themselves.
Source Boal et al., 2000(opens in a new tab)Source Fiorito et al., 1992(opens in a new tab)Octopuses can change the color, pattern and even the texture of their skin in a fraction of a second to match their surroundings. One species, the mimic octopus, goes further and impersonates other animals entirely.
Source Hanlon, 2007(opens in a new tab)Source Norman et al., 2001(opens in a new tab)The evidence increasingly says yes. In a 2021 study, octopuses avoided a chamber where they had experienced a painful injection and preferred one where they had received pain relief. That's behavior consistent with actually feeling pain, not just reflexively reacting to it.
Source Crook, 2021(opens in a new tab)A 2021 review commissioned by the UK government examined more than 300 scientific studies and found strong evidence that octopuses and other cephalopods are sentient. The UK's Animal Welfare (Sentience) Act 2022 now recognizes them as sentient beings. In the EU, cephalopods are protected under the rules governing animals used in scientific research.
In 2024, a group of leading researchers signed the New York Declaration on Animal Consciousness, stating there is at least a realistic possibility of conscious experience in cephalopod mollusks.
Source Birch et al., 2021(opens in a new tab)Source legislation.gov.uk, 2022(opens in a new tab)Source Official Journal of the European Union, 2010(opens in a new tab)Source New York University, 2024(opens in a new tab)As demand for octopus grows, companies have explored farming them. Researchers writing in Issues in Science and Technology argued against it: octopuses are curious, solitary, intelligent animals poorly suited to barren captive conditions, and as carnivores they would need to be fed other animals, adding pressure on wild fish populations.
Source Jacquet et al., 2019(opens in a new tab)
Photo by Nick Hobgood, CC BY-SA 3.0
No. Octopedarians eat whatever they want, just not octopus. It's one specific choice about one remarkable animal.
Absolutely. So did plenty of us. You can choose to be a Born-Again Octopedarian. Changing your mind after learning something new is worth celebrating.
Decades of research show octopuses solving problems, using tools, learning, playing and telling individual people apart. We link every claim on this site to its source so you can judge for yourself.
No. We don't do guilt here. Most of us didn't know how remarkable octopuses were until we looked into it. Learning something new and deciding differently is the whole point.
No. Membership is free. You get a member number, a membership card and a link to recruit friends.
Not at all. Ordering something else is enough. If you'd like to do more, our restaurant program will offer friendly, factual ways to help, never confrontation.
Every claim links to its source, and we favor peer-reviewed research and official reports. If you think we've gotten something wrong, email science@octopedarian.com.
They're fascinating too, and much of the science on this page applies to cephalopods broadly. Our pledge is about octopus. What you do with the rest is up to you.
Every fact on this page is backed by research. See all 33 sources