Cuttlefish 'talk' with their arms, study reveals | Hacker News Reader

Cuttlefish 'talk' with their arms, study reveals

scienceblog.com

145 pointsgeox103 comments

https://www.biorxiv.org/content/10.1101/2025.04.13.648584v3

It took me a while to find, but here is a BestOf Reddit comment from 16 years ago where a user Saydrah discusses communicating with Cuttlefish for an hour with her fingers https://www.reddit.com/r/funny/s/TBfh8u9MGX

I'm impressed you remembered and found a reddit comment from 16 years ago. +1 internet points

This would make my wife laugh so hard. If only I could remember more important things!

Uncannily similar

https://www.youtube.com/watch?v=KxOTbnHzGrI

The linked photo of the cuttlefish "greeting" gesture no longer exists where it was, but you can still see it here: https://web.archive.org/web/20071027131254/http://www.thepas...

   javascript free clickers,   
   can replace "www" with "old"  
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“Well that,” said Polynesia, brushing some crumbs off the corner of the table with her left foot—“that is what you call powers of observation—noticing the small things about birds and animals: the way they walk and move their heads and flip their wings; the way they sniff the air and twitch their whiskers and wiggle their tails. You have to notice all those little things if you want to learn animal language. For you see, lots of the animals hardly talk at all with their tongues; they use their breath or their tails or their feet instead.

Dr Dolittle’s Parrot explaining how to learn “animal language”. Voyages of Dr. Dolittle , chapter 8

Super cool! Imo kind of makes sense - think these sort of problems (communication) are general across actors and science seems to confirm some cases (between plants / funghi, cuddlefish, mamals..). Were not as unique as we think & thats freeing.

I see, so they share that with there main predator... Italians

Interesting, The Mountain in The Sea is becoming a reality.

https://www.goodreads.com/book/show/59808603-the-mountain-in...

I preordered it and read it with the expectation of getting great sci-fi about kraken and got something else entirely. The focus is on many things, but not on sci-fi and kraken, so it is one of the weaker books in this area, sadly. I finished it, but it was a slog.

I watched one checking me over when I was skin diving in about 3 feet of water. It was hard to see, because it had a rippling pattern of light and dark lines on its back that matched the sunlight through the waves.

In Peter Watts's novel Blindsight, alien entities known as "Scramblers" exhibit complex behaviors and high intelligence without evidence of consciousness, relying on intricate physical movements and environmental interactions.

This is so cool to see. When I used to do a lot of SCUBA diving I would sometimes have long staring competitions with cuttlefish. Of course it’s impossible to know for sure, but I always got the sense there was a lot going on behind those eyes.

>talk Cuttlefish don't talk. As far as we know the only species of animal capable of language are Humans. When people hear "talk" "communication" they believe it implies transmission of messages containing meaning through conscious thought. But for all other animals there is no evidence that either the sender nor the recipient generate or receive this meaning consciously.

In this universe humans are likely at the lowest level of consciousness.

So if I drum my fingers on the table, and my colleague gets visibly annoyed by it, these researchers think I am "talking" to him ?

Of course that's communcation. "Talking" might be a bit overpromising, but definitely some comms. Don't nitpick, the core is true. :P eyeroll

This is supposed to be science, terminology matters:

They state that tentacle waving serves "as a communication system between cuttlefish."

Merely showing that a thing reacts to another thing doing something in a certain way is NOT showing the existence of a communication system between them.

Weird. I would say that idle finger drumming is of course not communication.

> Communication is the process of exchanging information between individuals through various means, such as speaking, writing, or using body language. It involves a sender conveying a message to a receiver, who then interprets and responds to that message.

(some ai said this, but I think AI should be perfect for defining common words :)

Well to be fair finger drumming can, but does not have to be purpuseful communication.

You can drum your fingers because you are bored, not to signal to the outside that you are bored. Strictly speaking me picking up on your boredness because you drum your fingers makes it communication anyways I think :).

A better example would be waving at someone, communicating "hello / look at me / I see you / here / I'm happy to see you / goodbye"

Reading through this thread you can see how many people on HN don't understand non-verbal communication (note anotheryou, this isn't directed at you, you seem to get it).

I do wonder if some of these people realize they may not be neurotypical, even if just slightly. A huge amount of human behaviors and communications are encoded how we move and how our face reacts. If for some reason you can't pick up on or interpret this, then human behavior can be quite confusing.

In some sense everything is communication but that's going too far for "talking". In the more normal sense finger drumming can be communication but 90+% of the time it's not.

It would likely be better to describe that as an observation than a communication.

Even if someone were deliberately trying to convey they were bored via finger drumming, that communication only works in a social framework where we've mutually established a meaning to that behavior. If an alien were finger drumming on a table that would not necessarily indicate they were bored nonetheless that they wanted to convey that they were bored.

If I flip you off for being annoying, I would definitely be communicating something as specific as if I’d used words.

Yes, you’ll communicate your emotional immaturity. With words we might be able to solve the problem.

Don't forget about sign language.

Sign language is a language for people who have serious problems communicating with spoken language. So yes, definitely don’t forget about words communicated using sign language.

The signing community disagrees strongly with this take, as sign is an expressive artform in it's own right. Hearing folks can as easily appreciate a talented and expressive signer as a vocalist. And it's possible to express things through sign which are impossible to express with speech.

Heather Dale wrote a song about Gawain and the Green Knight, and produced a video in which a deaf storyteller tells the story while the song plays. (I don't think the story is an exact match to the song, but I assume it's fairly close.)

The storyteller uses some very impressive body language; it's great to see. It made me wonder if this is a particular strength of deaf storytelling, given that the audience has to be watching closely anyway.

https://www.youtube.com/watch?v=TTtlPUNGs3Q

99% of those people would not be interested in the artform if they or a loved one did not have a handicap.

Similarly, 99% of people will not appreciate an expressive signer as much as a vocalist.

That is just reality. I doesn't mean it is without value.

"Spanish is a language used by people who have serious difficulties communicating in English"

"But look, there are tons of people who speak English but still use Spanish to communicate with others who only or mostly speak Spanish"

"99% of those people would not be interested in Spanish if they or a loved one did not have problems speaking English".

Who are you quoting? That's obnoxious.

Are you claiming everyone can "easily appreciate" a Spanish language singer as much as one they actually speak?

"Hearing folks can as easily appreciate a talented and expressive signer as a vocalist. " is a silly claim.

If that were the case everyone would be going to sign language concerts they dont understand.

I never learned sign. Despite this, ASL is so expressive that I understand about half the words without training. Watching someone sign expressively is like watching dance (and the two are sometimes mixed). I don't need the words, it's beautiful.

Lots of folks feel similarly about opera.

It sounds like you've formed these opinions without ever exposing yourself to the things you have opinions about.

I don't have anything against it. I just think it is hyperbolic to say most people enjoy it on par.

Like I said in my original response, that's ok. It can be a valid art form with less mass appeal. More people like swift than Miles Davis. That doesn't invalidate Miles Davis.

>if they or a loved one did not have a handicap.

There are very strong opinions within the deaf community that it is not a handicap or disability and should be viewed more as a culture [1].

[1] https://muse.jhu.edu/article/31807

I take it you've never had a conversation on a dance floor, across a street busy with traffic, or without any risk of waking the baby (or your enemies, I guess), or behind somebody's (highly proximate) back.

Sign languages are for humans. Even those of us with sharp hearing can learn to take greater advantage of the bandwidth available to us.

There's nothing immature about flipping people off. In fact, it's quite healthy. Sometimes words fail, but flipping off never does.

Most HN posters were bullied in schools for being weird werent they

Who was never bullied during school age, maybe home schooled kids?

sorry, but i was never bullied (US public school)

The bullies...

I am engaging in the topic about nonverbal communication. Flipping the bird is not "talking" and is not some proper hearing impaired language, but is used to communicate very clearly. The parent comment was dismissive of the idea that cuttlefish "talked" with their tentacles and used an analogous situation to do so. I played off that original idea to show how much can be communicated. You only show your own character by jumping in just to attempt to belittle someone while missing the actual conversation.

The word "talk" doesn't appear anywhere in the article besides the title.

They grossly overstate what they have shown.

What they have actually shown - that cuttlefish react to another cuttlefish waving its tentacles - is clearly not showing that tentacle waving "serves as a communication system between cuttlefish.

I think you grossly overstate your expertise in marine communication studies.

How would you define communication between two entities? What threshold of data needs to be conveyed? Can communication be unidirectional?

Well data needs to be conveyed, as in there has to actually be a message. If one person yawns and that causes you to yawn, that is not evidence of communication - the first person was almost certainly not trying to send any information and you received none. Mimicking another's arm movement could be just as meaningless.

No that is precicsely communication, but nothing indicazes that is "talk". Communication is the "lower" phenomenon ghen talk/speech. Involuntary body processes communicate something in us sapiensapiens and we are sure tjat animals communicate. But do they talk... if we say "talk" ("sprechen") that entails the whole of what natural languages do and is quite different.

Again, reacting when an action is detected does not show communication.

I think you're confused about what the communication is.

The communication isn't the waving in "reaction" (it's not clear it's simply a reaction, but let's assume it is) to the original wave, but the original wave itself.

And the fact that it's also triggered by videos indicates it's not just a mechanical reaction (like some of the research about how plants "communicate" is which are essentially mechanical responses to stimuli).

However, this doesn't necessarily mean that the communication is meaningful. It just shows that a means of communicating exists.

"It just shows that a means of communicating exists."

That is my point. No confusion here.

I'm not going to speak for these researchers, but I will suggest you read up on the concept of scare quotes.

> The exact meaning behind these arm signs remains unclear. The researchers observed them in various contexts – during mating, hunting, defensive situations, and sometimes spontaneously. This suggests the signs might serve multiple purposes depending on the situation.

Can these signs be an alphabet of some language?

Squid are no big deal, but people should really stop eating cuttlefish and large octopi. By all accounts -- and, by now, there are very many -- they seem highly intelligent and playful.

If I donate my body to octopus stockfeed after I die (after organs are harvested for those in need obviously), does that give me a pass?

Can I kill and eat your pets and/or the pets of your friends/family?

I will donate my body as stockfeed to those remaining pets that your family/friends have after I die. Does that give me a pass?

But which pets do you mean. Pigs? Cows? Goats? A dog? A turtle?

Lots of places still eat horses, dogs or other animals. I may make a decision to not eat those but I don’t judge folks that do.

There’s a clear difference between deciding not to eat something for cultural reasons than deciding not to eat something because it’s an intelligent, thinking creature.

No it’s not, hence the conversation around it. I am glad you can draw that line clearly but don’t impose others to do the same.

If you swapped out "slavery", "rape", or "murder" for a few choice words in this thread, you can see how ridiculous your statement is. The way we treat and even talk about animals is an incredible moral failure.

You’re making my point for me. Swapping out words to create new moral equivalencies is exactly what I find unproductive. Humans are animals, and we live with competing instincts: survival, empathy, culture, appetite. In the best of times, we have the luxury to weigh those things and make personal choices. But pretending there’s a clean, universal moral framework that everyone must follow, regardless of history, biology, or circumstance, feels more like ideology than ethics. I respect your choices, just don’t expect everyone else to inhabit your frame.

You would find it unproductive since it makes your position obviously untenable. We use metaphors because they help short circuit whatever mental trappings you've managed to construct for yourself.

You're really just saying that it's not immoral enough for you to justify actually bothering to do anything about it, such as inconveniencing others with your opinion. I can pretty much guarantee you it was impolite for people to share their opinions against slavery back in the day, too. All I can really hope is future people will look back on today as a dark period of ignorance about animals and sentience.

I’m not dodging discomfort, I’m pointing out that morality isn’t just about drawing lines, it’s about understanding the context in which people live and make choices. You frame this as a binary: either one agrees with your comparison or they’re morally bankrupt. But that’s precisely why this conversation goes nowhere. I’m not defending factory farming, I’m pushing back on moral frameworks that flatten human behavior into easily judged categories. If you want lasting change, you have to start by recognizing that not everyone sees the world through the same lens, and that’s not always a failure of conscience.

You seemingly objected to

> There’s a clear difference between deciding not to eat something for cultural reasons than deciding not to eat something because it’s an intelligent, thinking creature.

I don't know how that turned into the conversation we have now. There is a clear difference between culturally choosing not to eat cute animals and being a conscientious objector. Whether you think it's harmful to take that stance publically or not is where we ended up.

I objected to the claim that the difference is clear. For many people, the lines between culture, ethics, and survival blur, especially across history or geography. What one person calls conscientious objection, another sees as cultural imperialism. That doesn’t mean we shouldn’t have values or push for change, but it does mean recognizing the complexity instead of assuming clarity where there is none. The conversation shifted because I challenged the framing, not the idea that reducing harm is valuable. I’m just wary of framing moral discourse as a purity test.

That's great for you. However, animals do not have a voice, despite being intelligent and feeling the same emotions as us. I am sure if you saw somebody harming a mentally disabled person who could not communicate, you would try to stop them. In the same way, I don't see any harm in being a voice for the animals.

For all we know, in the future we may look back on modern animal agriculture/ factory farming in the same way as we look back on slavery now.

If I can reduce harm in the world to sentient beings at the cost of something tasting slightly different then I will do my best to go down that path personally.

I respect your intentions, but the leap you’re making, comparing animal farming to slavery or abuse of disabled people, relies on swapping out real-world complexity for clean moral hypotheticals. Humans have always lived in tension between empathy and necessity. Culture, environment, and biology shape our choices more than abstract equivalence does. If you choose to avoid harm, great. But turning that into a universal moral indictment flattens history, species difference, and the human condition. We’re animals too, and sometimes we forget how messy that is.

Necessity is a flimsy justification. You could argue eating a little bit of meat is necessary for nutrition and survival. I wouldn't agree, especially if you live in a technically advanced nation, but you could argue it. What you can't really argue is that each American could possibly need to eat 200 chickens every year, or that the incredibly cruelty of their environments are warranted.

And if you stop elevating human sentience over everyone else for (??) reasons, it does become pretty black and white. Some people are still in the "recognizing it's an attrocity but still participating" stage, others are in the "actively (poorly) rationalizing the attrocity" stage, and many are in the "not yet realizing it's an attrocity" stage. Really only the people in the last one should get a pass, morally speaking.

You’re not describing moral clarity, you’re describing moral exceptionalism. You draw a clean line and then declare everyone outside it as ignorant, complicit, or cowardly. That’s not ethics, that’s dogma. Most people aren’t “rationalizing atrocities”, they’re living in the real world, where values collide with circumstance, biology, and culture. The “enlightened” always assume their version of truth is the final one, and they always seem to have the luxury to do so. That’s not moral progress, it’s just another flavor of certainty, polished by privilege and detached from the messiness of life. I am not justifying anything beyond refuting the clear lines you draw in your version of enlightenment.

The biggest impact when killing a pet is on the family, so that breaks the analogy really badly.

Just embrace cannibalism.

Now you can eat what you want without having to resort to hypocritical cladistics that don't match reality.

Watch out for prions. Stay safe.

Good advice. Fortunately for the aspiring cannibal, however, Creutzfeldt–Jakob disease is very rare with an estimated prevalence of 1 case per million people per year [1], and it's exposure to prions through the eating of infected meat that allows transmission this way rather than cannibalism specifically.

There's a popular belief that cannibalism can cause prion disease. However, this seems not to be the case with famous outbreaks such as Kuru being the result of many members of the community eating or being exposed to the brain tissue of already infected individuals [2]. Concern of transmission via eating meat of animals with a prion disease was the reason for European bans on British Beef in the 90s and 2000s [3].

If you're concerned about exposure to prion disease then good news! They are rare diseases and research suggests that most (87%) of the few cases that do occur are due to protein misfolding in the individual (spontaneous CJD) rather than genetics (familial CJD) or prion exposure (iatrogenic and variant CJD) [4].

[1] https://web.archive.org/web/20170704234755/https://www.ninds... [2] https://en.wikipedia.org/wiki/Kuru_(disease)#Transmission [3] https://en.wikipedia.org/wiki/Bovine_spongiform_encephalopat... [4] https://doi.org/10.1002%2Fana.410430611

On behalf of all of us cannibals, I'd like to express my sincere gratitude for this valuable contribution to our way of life.

Of course, but only if we talk about you dying now, via some pretty horrible death in well oiled industrial process, to make things at least a bit comparable.

Yes. You get to eat one.

I had a beautifully presented octopus tentacle tapas on Menorca about a decade ago. I can't describe how exquisite the meat is when cooked well.

But boy, all those short YouTube docs about smart octos just came flooding back at the first bite.

Felt a lot like eating someone's dog, and I've steered clear since.

To be fair, though: pretty much all animals normally die of starvation (if they're lucky) or are eaten alive. Depending on how they end up on your plate their life and end of it might be far less harrowing than what they face naturally.

It's not clear to me whether dying by starvation is always worse than being eaten alive. Some modes of being alive are definitely horrifying but others would result in a fairly quick death...

> pretty much all animals normally die of starvation (if they're lucky) or are eaten alive

You don't have to be eaten alive. There are predators who will kill their prey before eating it. Cats are known for that.

That's also why cats "play" with their prey. They're not being sadistic; they're tiring it out so they can safely make a killing bite, so they can safely eat it. When your food can bite back, it behooves you to kill it first, so it can't hurt you. Which matters when your ancestors (and potentially you if you're feral) were both predator and prey.

when you are being bitten to death, it is difficult to discern if you are being eaten by biting or just bitten by biting. this point goes to GP

The methods of killing cephalopods for commercial fishing aren't exactly what I would consider humane. Generally they are asphyxiated, thrown into freezing brine, or simply clubbed to death. There is a also a process called "reversing the mantle" which I can't find much information on but it is reported to be one of the less humane ways and frankly just the name sounds pretty terrible. Ironically the most humane method, slicing the brain, is avoided because customers don't like blade marks specifically because they believe it indicates mistreatment.

Pigs and birds are highly intelligent, too.

I take it you’ve never played hide and seek with a chicken

I have recently added unintelligent people to my "can eat" list since an arbitrary intelligence level is the indicator of whether it's ok to eat something.

Cuttlefish are incredibly intelligent.

Cuttlefish confirmed Italians

best comment

This is why I turned vegetarian. Fish, Chickens, Cows, Goats and other creatures are sentient.

Logically, it may make more sense to keep eating beef/some meat and instead give up dairy. Not only is it probably healthier, but the pain inflicted in the dairy industry is arguably worse per calorie than that of milk.

- Forced (artificial) insemination - Calf separation (within 24hrs of birth, causes distress to mother too) - Male calf fate (typically sold into veal or beef production, often under low-welfare conditions) - Repeated pregnancy and high milking demands (3–4 pregnancies over ~4 years and are milked 2–3 times daily) - Health problems (mastitis, lameness, metabolic disorders etc) - Physical mutilations (dehorning/disbudding, tail docking and branding are routine) - Early culling (Productive lifespan is ~5 years, yet natural lifespan ~20 years) - Confinement and barren housing - Transportation and slaughter

And what do you think will happen if today all dairy cows were released to open fields? (I know)

I’m cursious as to what would happen, other than more expensive milk and cheese

The cows would die if nobody milks them. Dairy cows are basically 100% reliant on humans now.

I live in a farming community but I'm not a farmer. I see comments about mistreatment of cows as if farmers are constantly beating them. Dairy farmers are one of the busiest types of farmers since cows have to be milked twice per day usually 04:00 and 16:00h (4am and 4pm).

Anyone with a business would not be damaging the product or causing it to fail from mistreatment. If a farmer mistreats cows the milk production drops. People comment have no clue about the farms and probably have never set foot on a farm or talked to a farmer.

I don't consider it, as the reduction in dairy consumption will likely happen over many years and as demand dies out, farmers simply reduce their dairy herd appropriately and repurpose the land.

So, you would rather keep mistreating them, because if we stopped mistreating them today it would mean they'd be slaughtered tomorrow? I'm quite sure what the cows would choose.

To drum a hollow drum, you probably meant sapient.

Sentience is a lower bar, and even most trees pass it. [0] Sentience, when boiled down, "just about" means capable of responding to pain. Nothing more. Sapience comes with the less easy to define intelligence of an individual.

[0] One of many, many papers in this debated topic: https://doi.org/10.1002/wcs.1578

Hollow drums are usually the best drums. If you fill them with stuff they don't resonate as well.

They can be loud and annoying for the neighbour.

not when they're deep-fried they don't

This is disappointing, I thought there would be a lot more cuddling involved

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