Fossil Amber Preserves Ecological Interactions between Ancient Ants and Other Organisms

Fossils trapped in amber are not only beautiful, they may preserve real ecological interactions, including possible parasitism or commensal relationships between ants and mites, as revealed by a new cutting-edge morphological study of six specimens of Baltic, Dominican and Burmese amber.

Fossil ant colony preserved in a piece of Baltic amber from Lithuania. Image credit: José de la Fuente and Agustín Estrada-Peña, doi: 10.3389/fevo.2026.1724595.

“Amber inclusions are representative of possible interactions between different organisms that shape the environment,” said Dr. José de la Fuente, a paleontologist at the Hunting and Wildlife Research Institute.

“The identification and morphological characterization of fossil ants in amber with other insect inclusions provides insight into life on Earth millions of years ago.”

In the new study, Dr. de la Fuente and his colleagues analyzed four pieces of amber from the Cretaceous (99 million years ago), one piece of amber from the Eocene (about 56 to 34 million years ago), and one piece of amber from the Oligocene (about 34 to 23 million years ago).

The specimens included ancient ants and other organisms, a rare phenomenon called syninclusion.

“The earliest ants, which were first found in the Late Cretaceous, are known as stem ants and did not leave modern descendants; all ants alive today evolved from crown ants,” the paleontologists said.

“Both species are found in the six pieces of amber we studied, as well as hell ants, which evolved from stem ants.”

The researchers used powerful microscopes to examine the specimens, identify the different species found inside, and measure the distance between the ants and other species.

In three of the six pieces of amber, they found ants in close proximity to mites.

In the first piece, they found a crowned ant, a wasp and two mites so close to the ant that they could have traveled on it.

The second piece contained a stem ant and a spider, while the third specimen contained a hell ant, a snail, a centipede and some unidentifiable insects.

The fourth specimen contained a stem ant and a mite, approximately 4 mm apart.

The fifth room also contained three different species of ants close to a mite and a few termites, as well as poorly preserved mosquitoes and a winged insect.

In the sixth specimen, scientists found a stem ant alongside a probable parasitic wasp and a spider. The ant seems to have fed on something.

It rests against another insect inclusion, which could be a worm or a larva, but since there is no indication that the two interact, scientists believe it is a coincidence.

“The closer ant syninclusions are more likely to reflect the behavior and interactions between these organisms,” Dr de la Fuente said.

“The ant-mite interactions proposed in the fourth specimen may reflect two possible scenarios.”

“First, a specialized commensal temporal relationship in which mites attach to ants to disperse freely to new habitats.”

“Second, parasitism when the mites feed on the host ant during transport.”

Although pieces of amber containing ants are rare, and pieces of amber containing multiple species are rarer, some published evidence indicates interactions between mites and ants, sometimes mutually beneficial.

Future research could help clarify this by using micro-CT to look for attachment structures on the mites that would have allowed them to climb aboard the ants for travel purposes.

“To improve the analysis of interactions between different organisms in fossil amber inclusions, future research should use advanced imaging techniques,” said Dr de la Fuente.

“Nevertheless, these results provide evidence of insect behavior and ecological habits.”

The team’s article appears today in the journal Frontiers of ecology and evolution.

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José de la Fuente and Agustín Estrada-Peña. 2026. Description of fossil amber with ant syninclusions. In front. Ecol. Evol 14; doi: 10.3389/fevo.2026.1724595