Behavioural adjustments enable the colonization of subterranean environments.

This article examines the convergent evolution of behavioural adaptations among subterranean species in response to the unique ecological constraints of underground environments, specifically constant darkness, limited food resources, and reduced predator pressure. Through a systematic review and quantitative analysis of 254 studies covering four behavioural categories—exploratory, anti-predator, foraging, and social behaviours—the authors found that species highly adapted to subterranean life (troglobites and troglophiles) generally exhibit reduced anti-predator responses and agonistic interactions, alongside broader trophic niches, compared to less adapted species (trogloxenes). While exploratory behaviour did not show significant differences, trends suggest more adapted species may explore more due to lower predation risk and reliance on non-visual senses. The study highlights behavioural plasticity as an early and stable adaptation facilitating subterranean colonization and calls for expanded research on diverse taxa, especially invertebrates and non-apex species, to deepen understanding of subterranean ethology.