Debate surrounds the role of behaviour in animal physiology, divided between traditional views that separate behaviour and physiology and a progressive perspective that supports the notion of behaviour as an inherent physiological effector. We advocate for the latter, and in this poster we provide a mechanistic and motivational perspective on behaviour and draw parallels with recognised physiological processes. Indeed, behaviour is ultimately generated by spatial and temporal patterns of musculoskeletal activity and it is tightly regulated by neural pathways, like other physiological processes. For example, many bird species will employ vasoconstriction and shivering – two well-established physiological processes in thermoregulation – and social huddling behaviour to avoid hypothermia. Yet, analogous neuroendocrine patterns can be observed in all three of these physiological actions. Furthermore, these responses are elicited by an animal’s motivational state in response to challenges in its environment. This motivational state can trigger a variety of physiological responses – behavioural or otherwise – that, while operating concurrently, all aim to satisfy an underlying ‘need’. For example, when an animal’s water balance approaches critical levels, it may employ a suite of physiological actions/strategies to conserve (e.g., water reabsorption in the gut, behavioural thermoregulation) and acquire water (e.g., water vapour absorption, drinking/feeding), driven by a motivational state to avoid osmotic stress. Our goal with this poster is to set the stage for a debate and persuade physiologists of the merits of including behaviour within the domain of animal physiology. Recognising behaviour as a physiological process is crucial for advancing a unified understanding of physiology.