Classical ethology, with its emphasis on separability of parts, has largely failed to do justice to the wholeness of the individual animal, to the integrity of group behaviour and to the continuity between observable behaviour and consciousness. Field theory has potentialities to do better, as illustrated in this paper with reference to morphogenetic and behavioural fields. A behavioural domain is delineated — playlike behaviour — where field theory is particularly relevant. It is shown that the concept of symmetry can suggest (...) new questions as well as explain some generally known phenomena of group behaviour. New interpretations of displacement activities and of etho-ecological adaptations are offered, both of which involve the whole individual animal. (shrink)