Eusociality is a characteristic observed in certain social animals, particularly insects, which describes a highly complex level of social organization and cooperation within a single colony or society. It refers to a system in which certain individuals within a group, often referred to as a "caste," specialize in specific tasks for the collective benefit of the group, rather than solely for their own survival and reproduction.
Eusocial species typically exhibit a reproductive division of labor, where only a few individuals, known as queens or reproductive members, are capable of reproducing, while the majority of individuals are non-reproductive and instead assume specific roles within the colony, such as workers or soldiers. This reproductive division is often accompanied by a high degree of cooperation and altruistic behavior among the non-reproductive members towards the reproductive individuals, ensuring the survival and prosperity of the entire group.
This level of organization often involves intricate communication systems, shared care of offspring, and cooperative resource acquisition and defense. Eusocial species are known for their elaborate nests or hives, sophisticated kin recognition, and complex pheromone signaling.
Eusociality is considered a highly evolved form of social behavior, as it requires individuals to prioritize the well-being of the group over their own individual interests. This phenomenon has been primarily observed in certain insect species, such as ants, bees, wasps, and termites, although there are a few examples in other animal groups as well. The study of eusociality provides valuable insights into the evolution of social behaviors and cooperative systems in both biology and sociology.
The word "eusociality" is derived from the combination of two Greek roots: "eu" meaning "good" or "true", and "social" meaning "pertaining to members of a community". The term was first coined in 1966 by biologist Charles D. Michener, who used it to describe a specific level of social organization found in some animal species. Eusociality refers to the highest level of social organization, characterized by cooperative care of offspring, overlapping generations, and division of labor among individuals in a colony or group. This term is commonly used in the field of biological sciences, particularly in the study of social insects like ants, bees, and termites.