This paper presents a collective animal behavior (CAB) algorithm for solving the multi-objective reactive power dispatch problem in power system. Modal analysis of the system is used for static voltage stability assessment. Loss minimization and maximization of voltage stability margin are taken as the objectives. Generator terminal voltages, reactive power generation of the capacitor banks and tap changing transformer setting are taken as the optimization variables A meta heuristic algorithm for global optimization called the collective animal behavior (CAB) is introduced.