Abstract. This paper makes two contributions to increasing the engagement of users in virtual heritage environments by adding virtual living creatures. This work is carried out on the context of models of the Mayan cities of Palenque and Calakmul. Firstly, it proposes a virtual guide system. The guide navigates a virtual world and tells stories about the locations within it, bringing to them its personality and role, so that differently characterised guides will produce different stories. Secondly, it develops an architecture for adding autonomous animals to virtual heritage. It develops an affective component for such animal agents in order to increase the realism of their flocking behaviour and adds a mechanism for transmitting emotion between animals via virtual pheromones, modelled as particles in a free expansion gas.