In this modeling scenario, we propose a gentle introduction to limit cycles using nullcline analysis and a spreadsheet graphical approach via the fourth-order Runge-Kutta method. We will be offering three predator-prey models, each more complex and real In mathematical ecology models, the existence of trajectories that exhibit cyclic behavior is a very important result. These trajectories are also called limit cycles.In general, finding limit cycles, or showing that there are no limit cycles to …