Are Ants Eusocial?

Yes, ants are eusocial. They’re among a select number of animals that exhibit eusociality. Their social organization is characterized by division of labor, cooperative care for brood, and generational overlap. 

Through this social organization, ants function as a superorganism. Each member of the colony fulfills their role to maximize productivity and resources. They all work together for the betterment of the colony.

In this article, we’ll learn more about eusociality as we discuss how and why ants are eusocial. 

Before all that though, let’s understand eusociality.

What Is Eusociality?

Eusociality is a form of social organization observed in certain insects like ants. It features cooperative behavior and specialized roles among individuals in a group. It’s characterized by the following: 

• Division Of Labor
• Cooperative Care For Brood
• Overlap Of Generations

In eusocial groups, individuals are divided into different castes. Each of these castes shoulders specific tasks and responsibilities to maximize productivity. [1]

How Are Ants Eusocial?

Eusociality is rather explicit in ants. Their colonies are divided into different castes that perform their respective roles. Each of these castes works together to ensure the survival of the colony. Together they form what is essentially a superorganism. See this article to learn more about ant colony structure.

Here’s how ants demonstrate eusociality:

Division of Labor

A remarkable example of ant eusociality is the reproductive division of labor. Queen ants are generally the only individuals in the colony that can lay eggs. All other females are sterile and are instead tasked with taking care of the queen and her brood. They collect food, keep the queen clean, and maintain ideal nest conditions.

This arrangement allows for the efficient use of resources within the colony. It ensures that the queen can devote all her energy to laying eggs and allowing the colony to grow.

Apart from reproduction, also further segments roles depending on other factors. For example, in some species, younger workers are assigned internal tasks where it’s safer. Older ones on the other hand are sent out of the nest to forage.

Cooperative Care for Brood

Cooperative brood care is a key characteristic of reproductive division of labor. Again, while the queen solely focuses on laying eggs, the workers do the rest. It’s up to the workers to make sure that the brood develops into mature ants.

By working together in caring for the brood, they ensure the survival and success of the colony.

Overlap of Generations

It isn’t uncommon for ant colonies to include multiple generations of ants. It’s simply part of their life cycle. Queens produce generations upon generations of workers that coexist within the colony. 

This overlap allows ant colonies to never run out of manpower and ensures that the colony will grow. They’ll continuously have workers that perform crucial tasks like foraging and brood care. See this article to learn more about worker ants.

Why are Ants Eusocial?

There are a number of theories that try to explain ants are eusocial. In general, these theories indicate eusociality as a means of survival. They also suggest that ants may have evolved to be eusocial to maximize the propagation of genes. [2]

These theories include the following:

• Kin Selection Theory
• Monogamy

Both kin selection and monogamy, use the concept of inclusive fitness. Inclusive fitness suggests that individuals can attain reproductive success by helping close relatives. This is because these close relatives share their genes. By helping them reproduce, the individual theoretically enhances its own genetic fitness. [3]

Which Other Animals are Eusocial?

Ants are not the only animals that exhibit eusocial behavior. They mostly occur in arthropods but have also been observed in mammals. Examples of eusocial animals include bees, wasps, termites, naked mole-rats, and shrimp.

Summary

To summarize, ants are eusocial. They follow a social organization characterized by the following:

• Division Of Labor
• Cooperative Care For Brood
• Overlap Of Generations

This rare organization has helped ants to become one of the most successful animals in the world.