Scientists discover “cleaner ants” that groom giant ants in Arizona desert

https://www.sciencedaily.com/releases/2026/04/260414075641.htm

by t-3 • 3 months ago

120 43 3 months ago

https://onlinelibrary.wiley.com/doi/10.1002/ece3.73308

https://www.nytimes.com/2026/04/13/science/harvester-cone-an... / https://archive.md/VEaPW

This is very cool, and quite surprising. Cleaner fish are thought to be among the most intelligent fish because of the complexity and danger of their feeding strategy: it takes careful planning and quick thinking. But they aren't tied to any particular species of host or general tactic; naively I imagine cleaner fish are more versatile and adaptable than cone ants.

It would be interesting to learn if this occurs with other species of ants. I suppose until now nobody thought to look.

lisper6• 3 months ago

Cooperation and symbiosis are very general survival strategies. They apear at all levels of the biological abstraction hierarchy, all the way down to mitochondria, which are almost certainly descended from what was once an independent organism. In fact, even a genome itself can be seen as a collection of mutually cooperating replicators. No intelligence is required for cooperation to evolve. It's a straightforward consequence of game theory.

fsckboy• 3 months ago

mmmm it's equally likely that mitochondria's precursors were self interested parasites or predators, whose negative effects were competitively neutralized by defensive host adaptations that exploititively colonialized them. No intelligence or cooperation is required for co-opt-ation to evolve. It's a straightforward consequence of game theory.

LeCompteSftware2• 3 months ago

This is a frustrating response to my comment. I am aware that symbiosis is universal. That's not what I'm talking about. I am talking about the specific and highly unusual behavior of crawling inside of a much larger animal's mouth and trusting it not to eat you. Cleaner fish are highly intelligent[1] and it appears that this intelligence is necessary for their niche:

- picking a good location for a cleaning station requires long-term planning and real strategic judgment;

- deciding which hosts to accept is a complex skill requiring some sort of rudimentary theory of mind + long-term development of social ties;

- like crows, cleaner fish are jerks who constantly try to screw each other over, so there is something of a cognition arms race.

I will add that the wrasse family of cleaner fish use rocks to smash open shellfish (i.e. they are tool-users), and they have very complex group strategies for raising their young. In fact I'm not convinced that wrasse evolved to be cleaner fish at all: they are natural scavengers and scum-suckers, perhaps cleaning stations are a form of cultural technology.

I would be extremely surprised if any of this was true for cone ants. I suspect that is more hard-wired, perhaps a local subspecies stumbled into a genetic fluke, and as you say due to game theory it is a local optimum this population has settled on. If this behavior were common like it is in vertebrates, we probably would have seen it earlier. But who knows? 20 years ago I would have thought "fish have a form of culture" is too ridiculous an idea to consider.

[1] Seriously: https://journals.library.columbia.edu/index.php/cusj/blog/vi... https://www.nature.com/articles/s41598-025-25837-0

culi3• 3 months ago

Yes! Cooperation seems to be just as fundamental, if not more, than competition. We wouldn't have gotten volcanic islands to break down into soil if it weren't for the partnership that is lichen. We wouldn't be able to digest a tenth of what we're able to eat if it weren't for our gut bacteria. We wouldn't have trees if it weren't for mycorrhizal fungi which over 90% of plants depend on.

There's a famous paper/framework called "Major evolutionary transitions in individuality" that sketches out a big picture pattern of major evolutionary advances in complexity following a surprisingly consistent pattern: As cooperation and division of labor strongly increase, selection starts working on larger entities. This pattern holds all the way back to the origin of life itself as things moved from self-assembling molecules to compartmentalized populations of molecules, from replicators to chromosomes, from RNA+enzymes to DNA+proteins, from prokaryotic cells to eukaryotic cells, from unicellular to multicellular, from individuals to colonies/superorganisms, and (possibly) onwards to more complex societies

https://www.pnas.org/doi/10.1073/pnas.1421402112

awinter-py• 3 months ago

this is no surprise to anyone who has read dougal dixon's 'man after man'

awakeasleep• 3 months ago

why haven't any animals adapted to this role for humans!

encrux• 3 months ago

In a Sense, cats did actually. Not through direct contact, but by getting rid of mice and rats that infiltrate food storage.

buildbot• 3 months ago

Cat’s will also literally try to clean you as well!

wizardforhire• 3 months ago

Lol!

Because there hasn’t been enough time and the ecological niche is non existent… ?

However… upon further inspection, one could argue that the micro biome is full of beneficial micro organisms that have evolved to fill this niche…

[1] Staphylococcus epidermidis

This is one of the most abundant and beneficial bacteria on human skin. It produces antimicrobial peptides and metabolites that inhibit the growth of pathogenic bacteria.

[2] Cutibacterium acnes

Despite its association with acne, this bacterium actually plays an important role in skin health by producing propionic acid, which helps maintain skin pH and prevents overgrowth of harmful organisms.

[3] Corynebacterium species

Various corynebacteria colonize the skin and produce lipases and other enzymes that help break down sebum (skin oils) and maintain healthy skin conditions.

[4] Malassezia species

These yeasts are abundant on skin and help regulate the skin microbiome, though they can sometimes cause issues in excess.

[1] https://en.wikipedia.org/wiki/Staphylococcus_epidermidis

[2] https://en.wikipedia.org/wiki/Cutibacterium_acnes

[3] https://en.wikipedia.org/wiki/Corynebacterium

[4] https://en.wikipedia.org/wiki/Malassezia

TeMPOraL• 3 months ago

How do you know they didn't? When was the last time you just let bugs spend time on you?

Joel_Mckay2• 3 months ago

There are more mites specialized to live on your eyebrows skin than many like to think about. =3

Joel_Mckay2• 3 months ago

There are many Garra rufa subspecies that were the source of compounds used in treating modern autoimmune and skin disorders.

The fishes histories go back thousands of years. As a species it is super interesting... some evolved in hot-spring conditions that would simply cook most other animals. =3

https://en.wikipedia.org/wiki/Red_garra

https://www.youtube.com/watch?v=CLWkojAnyH0

laidoffamazon• 3 months ago

Can we squint and say the gut microbiome is kind of like this?

sph• 3 months ago

Humans are the exoskeleton for gut bacteria.

victorbjorklund• 3 months ago

Plenty of bacteria lives in your guts feeding on your food and generating useful by-products.

Night_Thastus• 3 months ago

And plenty live on your skin, causing no harm but making it nearly impossible for dangerous bacteria to thrive.

t-3• 3 months ago

Apes commonly practice social grooming. So, humans are the animal adapted to this role for humans.

novia• 3 months ago

You too can let ants crawl all over you. They will find snacks.

thaumasiotes• 3 months ago

If you do this, you will start to develop spontaneous feelings of ants crawling all over you whether or not they're really there. I wouldn't recommend it.

lovich• 3 months ago

most people find it disgusting, but some rat owners will let their rats clean their teeth and the rats seem to enjoy the activity much like how other social animals enjoy grooming each other

Rexxar• 3 months ago

This one is doing the job on almost every body you know: https://en.wikipedia.org/wiki/Demodex

marojejian• 3 months ago

NYT story earlier on this: https://news.ycombinator.com/item?id=47754440

riazrizvi• 3 months ago

They crawl over them and lick and nibble their bodies? Okay I understand the quotes now.

It truly is the oldest profession.

mmooss• 3 months ago

The full paper described in the article is available here:

https://pmc.ncbi.nlm.nih.gov/articles/PMC13070876/

Mark W. Moffett. The First Cleaner Ant? A Novel Partnership in the Arizona Desert. Ecology and Evolution, 2026; 16 (4) DOI: 10.1002/ece3.73308

shawn_w• 3 months ago

I'm more concerned about the giant desert ants. I've seen that movie...

emmelaich• 3 months ago

Or jungle ants...

"Commissioner: Leiningen, you're up against a monster twenty miles long and two miles wide... forty square miles of agonizing death! You can't stop it!"

-- quote from The Naked Jungle.

Trivia - I believe this is from where Clojure got their build tool name.

kwertyoowiyop• 3 months ago

The movie is from the classic original story “Leinengen Versus the Ants”:

The Brazilian official threw up lean and lanky arms and clawed the air with wildly distended fingers. "Leiningen!" he shouted. "You're insane! They're not creatures you can fight--they're an elemental--an 'act of God!' Ten miles long, two miles wide--ants, nothing but ants!”

14• 3 months ago

I am surprised they used the comparison of the fish over the practice of "anting" which is a behavior that more than 200 species of birds do in which they will land on an ant next and allow ants to crawl all over them. The theory being that the ants release formic acid which is a natural defense against parasites, fungi and mites.

I have a couple ant nests on my property and have witnessed several crows at a time land on the nests and do this behaviour on multiple occasions.

What ever the reason the bigger ants are allowing this to happen I am convinced that there is some sort of beneficial reason.

x______________• 3 months ago

I have a couple ant nests on my property and have witnessed several crows at a time land on the nests and do this behaviour on multiple occasions.

Would love to see some video footage of this!

occamofsandwich• 3 months ago

What ever the reason the bigger ants are allowing this to happen I am convinced that there is some sort of beneficial reason.

Isn't it an opportunity to find lice and ticks?

Scientists discover “cleaner ants” that groom giant ants in Arizona desert

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