A new study reveals that some ant species achieve evolutionary success by investing less in individual worker protection, allowing for larger colonies. Published on December 19, 2025, in Science Advances, the research analyzed over 500 ant species and links thinner cuticles to bigger societies and higher diversification rates. This strategy echoes broader patterns in social evolution, from insects to potentially human parallels.
Researchers have uncovered how certain ant species gained an evolutionary edge by favoring quantity over quality in their workforce. Instead of building robust armor for each ant, these species allocate fewer resources to the cuticle—the exoskeleton's protective outer layer—freeing up nutrients to produce more workers. This shift enables colonies to grow larger, compensating for individual vulnerability through collective behaviors like group defense and coordinated foraging.
The study, led by Arthur Matte of the University of Cambridge and senior author Evan Economo of the University of Maryland, examined 3D X-ray scans from more than 500 ant species. They found cuticle investment ranging from 6% to 35% of an ant's body volume. Evolutionary models showed that species with lower cuticle proportions formed bigger colonies, from dozens to millions of members.
"Ants reduce per-worker investment in one of the most nutritionally expensive tissues for the good of the collective," Matte explained. "They're shifting from self-investment toward a distributed workforce, resulting in more complex societies."
This approach also correlates with accelerated diversification, a key indicator of evolutionary success. Lower nutritional demands, particularly for nitrogen and minerals, may allow these ants to thrive in resource-scarce environments. Economo described it as "the evolution of squishability," noting how reduced individual robustness fosters group-level adaptations.
The findings draw parallels to other social systems, suggesting similar paths in termites and even human history, such as the transition from armored knights to mass infantry under Lanchester's Laws. As Matte put it, "The tradeoff between quantity and quality is all around." The paper highlights how simpler individuals can drive complex societies, mirroring the rise of multicellularity.
