The topic of decentralized system is not widely discussed nowadays. The present paper is one of the first attempts to discuss the topic and it is devoted to work with children. It deals with decentralized systems and programmes for theirs modelling. Firstly, the paper tries to find out whether decentralized system really exit by deeper analysis of special programmes for work with programme, explains how it works and gives a translated list of commands. Several modellings were made: providing an anthill with food, the drawing of graphic ornaments and the fire in a forest. The results showed that there is no need for centralized ruling when seeking for the aim of the system. It is enough that agents perform the same actions. The results of the paper could be used at school in an integrated lesion of biology, information technologies and geography or in an information technologies lesion.