The ecological success and the unique features of social insects makes them prime objects in both evolutionary and ecological research. Social insects, however, also share a multitude of traits with plants, including competitive interactions between neighboring units. In particular, multinest societies of ants resemble in many respects vegetative propagating plants - both are tied to a site of growth/nest, both produce ramets or daughter nests and engage in long-range sexual dispersal mediated by sexual entities. Several recent models have considered the effects of competition of growth patterns and territory size in plants. Given the striking parallels that exist between ants and plants, such models can be expanded so that predictions can be derived for ant colonies. However, no studies have explored these possibilities. My aim is to expand current theory on competitive interaction in plants to generate predictions that can be tested in multinest societies of ants. Furthermore, I will test these predictions empirically in two species of ants, Formica truncorum and F polyctena, which differ in their degree of population sub structuring and therefore the intensity in competitive interactions. The results will provide new insights into levels of selection theory , kin selection theory as well as the spatial ecology and population dynamics of multiqueen, multinest societies of ants, and will be a significant contribution in understanding the ecological success of such societies. The host institute has a strong international reputation and excellent expertise in both experimental and theoretical work. Weekly high-profile seminars in English with frequent international guests guarantee contacts with a broad range of topics in ecology and evolution. The "Spatial Ecology" programme, hosted by L. Sundstroem, I. Hanski, E. Ranta and J. Niemelae organizes yearly workshops that facilitate new contacts and provide ample opportunities to interact with leading ecologists/evolutionary biologists. The host group is a subcontractor in an EU-funded TMR network (INSECTS), and has very strong expertise in the proposed research field, including the requirements associated with fieldwork and laboratory experiments on the species at hand. Through the network I will have the opportunity to collaborate with Prof. P. Pamilo at Oulu University. I will benefit dramatically, in terms of research skills and career development, from all of these opportunities, as well as being able to develop new and exciting research. In turn, the proposed project will enable the host group to expand into new research areas and establish contacts for future collaboration.