A model of food recruitment by social insects accounting for the competition between trails in the presence of an arbitrary number of sources is developed and analysed in detail. Both the case of identical environmental characteristics and the case where one source and the corresponding trail are different from the others are considered. Different collective responses depending on the environmental conditions, and without change of individual behaviour, are shown to exist, associated with the possibility that the colony may be led to exploit one source or a group of sources preferentially. The full bifurcation diagram of steady-state solutions is constructed from which the dominant exploitation patterns are identified. The biological relevance of the results is discussed and suggestions are made for their experimental testing in connection with the recruitment behavior of species using trail recruitment. The same phenomenological model can be used for different trail-laying species since the predictions are generic and not restricted to a given species, except for the parameter values used. Copyright 1999 Academic Press.