At a Glance
- A recent study reveals that mammals have independently evolved to exclusively eat ants and termites, a diet known as myrmecophagy, on at least 12 separate occasions since the Cenozoic era began.
- This evolutionary trend was driven by the massive global expansion of ant and termite populations, which became a reliable and abundant food source only after the extinction of the dinosaurs.
- All specialized anteaters evolved from ancestors that were either general insectivores or carnivores, with the transition from insect-eating being three times more common than from meat-eating.
- The research found only one instance of a myrmecophagous lineage reverting to a more general diet, suggesting this extreme specialization is a nearly irreversible evolutionary path or dead end.
- Despite its limitations, this dietary strategy has proven successful for specialists like anteaters and aardvarks, which may gain an advantage as climate change favors large social insect colonies.
A new study reveals that since the age of dinosaurs ended, mammals have independently evolved to eat ants and termites at least 12 separate times. This extreme dietary strategy, known as myrmecophagy, involves developing highly specialized traits, such as long tongues and reduced teeth, to consume thousands of insects daily. Published in the journal Evolution, the research shows how these unique mammals emerged only after their food source became widespread.
The global takeover by ants and termites began after the mass extinction event that wiped out the non-avian dinosaurs about 66 million years ago. Researchers traced the history of these insects, finding that while they originated earlier, their numbers increased significantly during the Cenozoic era, making them a dominant and reliable food source. This ecological shift created a powerful selective pressure, prompting some mammals to adapt to this abundant but low-energy food. “Their sheer biomass set off a cascade of evolutionary responses,” said Phillip Barden, the study’s corresponding author from the New Jersey Institute of Technology.
To uncover this evolutionary roadmap, scientists compiled dietary information for 4,099 mammal species and mapped it onto a family tree. They found that transitions to myrmecophagy always came from ancestors that were either general insect-eaters or meat-eaters, with insectivores making the leap more frequently. Despite evolving in every major mammal group—including monotremes, marsupials, and placentals—this specialized diet is rare. “Few rely exclusively on ants and termites […] the ecomorphological adaptations required are such a major barrier,” said co-author Thomas Vida of the University of Bonn.
Once a species commits to myrmecophagy, it rarely reverts to its previous behavior. The study found only one instance of a mammal reverting to a more general diet after becoming a specialist. This suggests that specializing on ants and termites may be an evolutionary “dead end,” locking species into a diet they cannot escape. However, as long as social insects continue to thrive, these specialists have a secure food source, which Barden notes could be an advantage as climate change may favor the very insects these mammals eat.
References
- Jenkins, J. & New Jersey Institute of Technology. (2025, July 16). Mammals have evolved into ant eaters 12 times since the dinosaur age, study finds. Phys.Org; New Jersey Institute of Technology. https://phys.org/news/2025-07-mammals-evolved-ant-eaters-dinosaur.html
- Vida, T., Calamari, Z. T., & Barden, P. (2025). Post K-Pg rise in ant and termite prevalence underlies convergent dietary specialization in mammals. Evolution, qpaf121. https://doi.org/10.1093/evolut/qpaf121
