Eliminative behaviour is the act of urination and defecation, including site selection, posture, timing, and environmental interactions is a fundamental component of animal biology influencing welfare, communication, and ecosystem processes. This review synthesizes literature on eliminative behaviour across domestic livestock, companion, and wild species to elucidate its evolutionary, physiological, and management significance. In domestic systems, studies in cattle, pigs, horses, and poultry show that elimination patterns are shaped by housing, social context, and environmental enrichment, with implications for hygiene, ammonia emissions, and disease transmission. In wild mammals, such as ungulates and carnivores, elimination often serves social and territorial functions mediated by olfactory cues, reinforcing dominance and spatial organization. Avian and reptilian species demonstrate environmental and thermoregulatory influences on excretory behaviour, linking elimination with microhabitat selection and predator avoidance. Recent ethological advances reveal that eliminative acts are not random waste processes but adaptive behaviours balancing cleanliness, communication, and energetics. Comparative analyses indicate strong phylogenetic conservation of site avoidance near resting and feeding zones across taxa, supporting an evolutionary drive for parasite risk reduction. From a management perspective, understanding eliminative preferences enables design of welfare-oriented facilities and ecological restoration strategies by aligning behavioural needs with spatial layouts. Integrating behavioural ecology with animal welfare and environmental management offers new avenues for improving husbandry, mitigating emissions, and enhancing health across managed and wild populations.