Any self-suucient autonomous agent faces multiple tasks to which it must sequence its behaviour if it is to manage its time appropriately. This paper considers the minimal multiple task scenario-the two resource problem. Some possible mechanisms, inspired from ideas in ethology and having claim to perform optimally when analysed mathematically , are considered: one based on cost functions and another based on motivational tendencies. Several variants of the mechanisms are implemented and tested in a continuous two dimensional simulation environment under a variety of conditions. Those mechanisms closely linked to cost functions do not perform well, are not adaptive, and dither. The mechanisms based on mo-tivational tendencies perform better, are more adaptive, and demonstrate opportunism. The diiculty of nding eeective mechanisms by using a functional perspective is noted.