Primates are generally social animals, interacting with each other using facial expressions, vocalisations and body language, just like humans do. These interactions can be complex and although we may study them through observation, we can learn more about how individual monkeys perceive each other by conducting social experiments with them in a more controlled environment. In order to understand more about social interactions in long-tailed macaques, we have begun to develop a monkey ‘avatar’ which looks and behaves like a real monkey, and can be controlled to ‘interact’ with a real monkey. The virtual monkey can move its head and eyes and make four different facial expressions, which can be controlled by an experimenter in real-time. Thus, we can examine how a free-moving monkey responds to its virtual counterpart in different social contexts, providing us with the ‘control’ we need to examine social interactions in more detail.