The phenomenon of colonialism which characterizes many insect groups is considered in terms of its potential effect on intraspecific competition. Intraspecific competition is assumed to be a function of the number of distinct pair encounters between 2 individuals of differing colony origin. A model is offered which describes the reduction in the number of potential competing encounters as a result of colonialism, and as such, combinatorial formulae are appropriate. For 2-colony and multi-colony systems, there is a proportionately smaller number of potential competing encounters as the size of the colonies becomes more inequitable and greater than 100 individuals in combined total. As a consequence, large inequitabilities in colony sizes are expected for nearest neighbor pairs, and thus a generally large variance in colony size for groups of colonies is also expected. Empirical data from various sources is presented and in good agreement with the predictions generated from the model.