In Arizona's desert, tiny ants turn into living hygienists, climbing inside bigger ants' mandibles and cleaning them

Paul Arnold

contributing writer

Meet our staff & contributors
Learn about our editorial standards

Lisa Lock

scientific editor

Meet our editorial team
Behind our editorial process

Robert Egan

associate editor

Meet our editorial team
Behind our editorial process
Editors' notes

This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility:

fact-checked

peer-reviewed publication

trusted source

proofread

The GIST
Add as preferred source

Ants are known for many things. They fight, bite and sometimes compete for every crumb. We can now possibly add cleaning services to that list, according to a study published in the journal Ecology and Evolution.

Desert discovery

In June 2006, Mark Moffett, an entomologist at the Smithsonian National Museum of Natural History, observed and photographed an unusual interaction in the Arizona desert between two different ant species. He had hoped to return to the desert to collect more data, but never made it back. Consequently, his paper is based on observations he made during a five-day window 20 years ago. He explained that he is publishing them now, in part, because no one else has reported this behavior.

While sitting behind a cottage in the desert, he saw large harvester ants (Pogonomyrmex barbatus) stand completely still near the nests of cone ants (an undescribed Dorymyrmex species) while these smaller insects crawled all over them. As well as taking high-resolution photographs, Moffett wrote in detail about what he saw, recording at least 90 separate interactions.

They tended to follow a similar pattern. A harvester would sometimes approach the entrance of a cone ant nest and adopt a stiff posture, often with their jaws wide open and legs extended.

The cone ants would then lick and nip at the harvester ant's body and even clean inside their open mandibles. During these sessions, the harvester ants never attacked the smaller insects. It reminded Moffett of how some fish inspect the mouths of large predators.

"I became increasingly convinced that this Dorymyrmex was the first recorded 'cleaner ant,'" wrote Moffett in his paper.

Insect cooperation

To test this hypothesis, he left dead harvesters near the cone ant nests. While they briefly examined the bodies, they did not perform the licking and nipping behavior. This suggests that it depends on signals from living ants rather than it being a case of the smaller creatures scavenging for food.

Moffett contacted several leading biologists to help explain why the ants act this way. For harvesters, cleaning might remove pathogens from hard-to-reach areas. It could also be that cone ants transfer antifungal or antibacterial substances onto the larger ants during the process.

For the cone ants, the partnership may offer protection. Constant contact might transfer harvester pheromones that reduce aggression from the bigger insects. They may also get a nutritional boost by eating oils or other compounds found on the harvester ant's shell.

While many questions remain unanswered, the research at least provides a rare glimpse into a more harmonious side of insect life, as the entomologist notes: "In a world where most ants steal, fight, and outmaneuver one another, it seems that two species in an Arizona desert leave room for an unexpected collaboration."

Written for you by our author Paul Arnold, edited by Lisa Lock, and fact-checked and reviewed by Robert Egan—this article is the result of careful human work. We rely on readers like you to keep independent science journalism alive. If this reporting matters to you, please consider a donation (especially monthly). You'll get an ad-free account as a thank-you.

Publication details

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

Journal information: Ecology and Evolution

Key concepts

animal behaviorsymbiosisCollective behavior

© 2026 Science X Network