Summary
Social organisation with reproductive division of labour, overlapping generations and cooperative care, as in ants and bees.
In depth
Characteristics: cooperative brood care, reproductive castes (queen, workers) and overlapping generations. Found in ants, bees, wasps, termites, naked mole-rats and some shrimps. Workers' sterility is explained by kin selection.
Eusocial colonies have division of labour. Termite colonies have kings and queens. Chemical signals regulate castes.
Example: naked mole-rats are the only eusocial mammals mentioned commonly.
Eusociality has arisen in insects (ants, bees, wasps, termites, some beetles and aphids), snapping shrimps (Synalpheus) and two mammals, the naked mole-rat and Damaraland mole-rat. Colonies function as superorganisms with division of labour: queens lay eggs, workers forage, nurse and defend, and soldiers guard. Caste determination may depend on diet (royal jelly in bees) or genetics.
Explanations include kin selection (Hamilton), with haplodiploidy increasing relatedness, and ecological benefits such as defended nests, which may precede eusociality. Wilson and others have argued for group selection, a view that was debated. Colonies communicate with pheromones, and some ants farm fungi or aphids, and leafcutter colonies reach millions.
Example: a honeybee colony can hold 50,000 workers, with a single queen laying up to 2000 eggs a day.
Frequently asked questions
What is Eusociality?
Social organisation with reproductive division of labour, overlapping generations and cooperative care, as in ants and bees.
Which area of biology covers Eusociality, and how advanced is it?
Eusociality is one of the 53 topics in Zoology & Animal Diversity. It is rated Advanced, so it suits learners who want specialist depth. Related topics in this area include Insect Haplodiploidy, Parasitism in Animals, Domestication Genetics.
Can you give an example of Eusociality?
Leafcutter ants farm fungus.
What should I learn before Eusociality?
Work through the Beginner topics in Zoology & Animal Diversity first, such as Animal Kingdom, Vertebrates and Invertebrates, Sponges, then return to Eusociality. Advanced topics assume the Intermediate vocabulary.
What topics are related to Eusociality?
The closest topics to Eusociality are Insect Haplodiploidy, Parasitism in Animals, Domestication Genetics, Mammals. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Eusociality?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Eusociality. To practise the whole of Zoology & Animal Diversity, use the Zoology & Animal Diversity quiz.
How is Eusociality different from Insect Haplodiploidy?
Eusociality: Social organisation with reproductive division of labour, overlapping generations and cooperative care, as in ants and bees. Insect Haplodiploidy: Males are haploid and females diploid in Hymenoptera, shaping relatedness and sociality. Read both side by side and note what each one explains.
How should I study Eusociality step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Insect Haplodiploidy and explain the difference aloud. Finally, take the Zoology & Animal Diversity quiz and come back to this page for any question you miss.