First-of-its-Kind "Cleaner Ants" Discovered Grooming Giant Harvester Ants in Arizona Desert

Entomologists discover tiny "cleaner ants" in Arizona that groom giant harvester ants, even inside their jaws, in a first-of-its-kind insect partnership.

By: AXL Media

Published: Apr 15, 2026, 10:06 AM EDT

Source: Information for this report was sourced from Smithsonian / ScienceDaily

A Desert Version of the Marine Cleaning Station

A groundbreaking study published this week in the journal Ecology and Evolution has revealed a sophisticated and previously unknown partnership between two ant species in southeastern Arizona. While observing ants in the Chiricahua Mountains, Smithsonian research associate and entomologist Mark Moffett discovered that tiny cone ants (Dorymyrmex sp.) serve as "cleaners" for significantly larger harvester ants (Pogonomyrmex barbatus). This interaction closely resembles the mutualistic "cleaning stations" found in coral reefs, where small fish and shrimp remove parasites from larger, potentially predatory fish.

Delicate Grooming Between Lethal Jaws

The documented behavior follows a highly specific and cooperative ritual. A large harvester ant will approach the nest of the much smaller cone ants and assume a distinct "stiff" posture, standing high on its legs with its serrated mandibles wide open. Instead of an aggressive response, tiny cone ants emerge and begin meticulously licking and nibbling the harvester ant’s body. Most notably, the larger ants remain completely motionless while the visitors venture between their open jaws to groom hard-to-reach areas. These sessions can last anywhere from 15 seconds to over five minutes.

Mutual Benefits: Nutrients for Hygiene

Researchers are currently analyzing the evolutionary advantages of this behavior for both species. Moffett suggests that the cone ants are likely feeding on energy-rich microscopic particles, such as seed fragments or debris, that they "squeegee" off the larger ants' exoskeletons. For the harvester ants, the benefit appears to be superior hygiene; while they are known to groom their own nestmates, the tiny size of the cone ants allows them to reach crevices and parasites that larger ants cannot access, potentially reducing the risk of fungal or bacterial infections.