Subterranean mammalian societies: identity and social architecture in eusocial mole-rats

Societies are more than groups of animals coexisting; they are structured, enduring communities defined by stable membership, shared identity and relationships that persist across generations. Among mammals, such societies are uncommon but reach their most extreme form in the eusocial African mole-rats, namely the naked mole-rat, Heterocephalus glaber , and the Damaraland mole-rat, Fukomys damarensis . Eusociality, well known from ants, bees and termites, is a social system loosely comparable to a monarchy, in which a single breeding queen and one or a few males monopolize the colony's reproduction, while other group members suppress their own reproductive potential to serve the needs of the colony. These mole-rats are among the only mammals to fully embody this system, forming long-lived, cooperative colonies with strict boundaries between colony members and outsiders. Yet their strategies for social cohesion diverge. Fukomys damarensis depends primarily on individual familiarity to maintain group identity, thereby limiting colony size. In contrast, H. glaber uses a shared colony scent and distinct colony-specific vocal dialect to support larger, scalable societies. By comparing these societal extremes, this review explores what makes societies stable, exclusive and resilient, while highlighting the gaps in our current knowledge.