Modeling is helpful to understand integrated pest management (IPM) systems and to develop and test new methods of control. Modeling is also useful in predicting pest outbreaks, although the high number of variables makes this risky and difficult to achieve. Many aspects of the biology and ecological interactions can be understood better through the use of models which can be verbally, visually, or computer generated. Dispersal is the process whereby a cohort of individuals moves from an origin (e.g., birth place) to a new site for improving the quality of their food and habitat. For example, aphids may develop on a plant that is maturing and its leaves are drying out due to age and insect feeding damage. There comes a point in time when it is more advantageous for the aphids to undertake a dispersal flight to find a new food plant even though there are considerable risks in searching for a new place because of increased exposure to predators and heat/water stresses, among other dangers. Similarly, many insects must find a new food source, or a mate during their life cycle. An understanding of the dispersal phases, i.e. how far, how often, and risks involved, is crucial to constructing better IPM systems. The use of models is practically unlimited and they can be made continually more useful both through better algorithms and by faster computers.