Division of labor in ants, or where different ant have different jobs, is a vital part of what makes ant colonies so successful. Each ant has specific roles to help the entire colony run smoothly and efficiently. These roles are not only about what each ant does but also about physical and internal differences that match them to their tasks.
Many ant queens have the ability to expand their abdomens as they activate more ovaries
For example, queens focus on reproduction, while foragers are equipped to handle exposure to outside risks, and nest-workers are adapted to help with digestion and nest maintenance. These specializations mean that each ant performs the tasks it’s best suited for, making the whole colony more effective.
Ants don’t pick their jobs based on a conscious choice; instead, they take on tasks suited to their physical traits, age, and pheromone signals from other ants. Some roles, like foraging and brood care, are common in many species, while specialized tasks like phragmotic guarding or replete food storage are unique to certain types of ants.
Research shows that this division of labor even influences how long different ants live. Queens live much longer than worker ants, possibly due to energy trade-offs that help the colony fight off infections and stay healthy. This organization means ants can respond to challenges in their environment better and get the most out of their resources. The division of labor allows each ant colony to work like a well-organized team, with each member playing a unique role in the group’s survival and success.
Age and Experience: Taking on Different Roles Over Time
In most ant species, the jobs an ant performs can change as it ages, with younger ants often working within the nest and older ants taking on more dangerous external tasks.
Typically, worker ants are lighter in color when they're young, as their exoskeletons harden and develop color over time
Younger ants may start with tasks like brood care or nest maintenance, protecting and feeding the developing larvae. As they age and gain experience, they may transition to more dangerous roles, like foraging or colony defense outside the nest. By progressing through different roles over their lifetimes, ants maximize their contributions to the colony while balancing the risks they face.
Similarly, there is often a age-segregated spectrum in the nest, with older workers, who often do the most risky tasks, being far away from the queen, in case they spread disease.
In cases where a sudden demand arises—such as an increased need for foragers—older ants can quickly step in, adding flexibility to the colony’s workforce.
In mature colonies, between 40-90% of ants are reserve workers. They have no specific tasks, but they look for work and step in where more of a given role is needed.
Physical Differences in Roles
Some jobs are determined by an ant’s physical characteristics, which means certain roles are possible only for specific species. For example, phragmotic workers have flat, shield-like heads that function like living doors, blocking nest entrances to keep out intruders.
Cephalotes majors have shield-shaped heads to block off their nest entrances
Only ants with this head structure, like turtle ants (Cephalotes sp) or Cork head ants (Colobopsis sp), can perform this task. Their body shape and size allow them to fit precisely into entrance holes, making them a natural fit for guard duty.
Prenolepis imparis (false honeypot ant) queen and workers
Another example of a role based on physical traits is the replete worker. In honey ant species like Myrmecocystus, repletes store food in their bodies, swelling up like living pantries to provide nourishment during food shortages. These roles aren’t available to all ants but depend on unique body adaptations suited to certain species' environments.
Pheidole sexdentata have different types of workers for different roles
One trait common across many ant species are majors which specialize in colony defense or food processing. These larger, stronger workers react to alarm pheromones when an outside threat is detected. These ants stand guard near the nest entrance, ready to ward off intruders, which keeps the nest secure from potential predators or rival ants. In many species, they also crush hard foods, such as seeds or insect exoskeletons into more easily digestible forms.
Pheromone Signals: Communicating Roles in the Colony
In many cases, ants are guided to their jobs by chemical signals, or pheromones, that tell them where help is needed. Paramedic ants haul the wounded home but also tend to their injuries, cleaning wounds and perhaps even using antimicrobial substances to prevent infections.
Pristomyrmex worker brings back dead beetle
Undertaker ants, which remove dead ants from the nest to prevent disease, are also guided by pheromones. When an ant dies, it releases necromones (mainly oleic acid), which signal certain workers to carry the body away from the nest, helping maintain a healthy environment. Through these chemical messages, ants know when and where to step into action, keeping the colony safe and clean. Waste management roles often taken on by ants who have lower immunity or are nearing the end of their lifespan.
Conclusion: An Efficient, Adaptable Society
Ant colonies are an impressive example of efficiency and adaptability, with tasks chosen by a combination of physical traits, pheromone communication, and environmental needs. From phragmotic guards and repletes to underakers and nurses, every ant plays a critical part in keeping the colony safe, healthy, and well-fed. By naturally dividing labor based on physical characteristics, experience, and pheromone signals, ants create a complex and highly organized society that’s built to thrive—even in the toughest conditions.
Further Reading
Chiu, M.-C., Wu, W.-J., & Lai, L.-C. (2019). Carriers and cutters: Size-dependent caste polyethism in the tropical fire ant (Solenopsis geminata). Bulletin of Entomological Research, 110(3), 388–396. https://doi.org/10.1017/s0007485319000750
Di Pietro, V., Govoni, P., Chan, K.H. et al. Evolution of self-organised division of labour driven by stigmergy in leaf-cutter ants. Sci Rep 12, 21971 (2022). https://doi.org/10.1038/s41598-022-26324-6
Frank, E. T., & Linsenmair, K. E. (2017). Individual versus collective decision making: Optimal foraging in the group-hunting termite specialist Megaponera analis. Animal Behaviour, 130, 27–35. https://doi.org/10.1016/j.anbehav.2017.06.010
Gordon DM. From division of labor to the collective behavior of social insects. Behav Ecol Sociobiol. 2016;70(7):1101-1108. doi: 10.1007/s00265-015-2045-3. Epub 2015 Dec 2. PMID: 27397966; PMCID: PMC4917577.
Powell, S. (2008). Ecological specialization and the evolution of a specialized caste in Cephalotes ants. Functional Ecology, 22(5), 902–911. https://doi.org/10.1111/j.1365-2435.2008.01436.x