A. How long pests may be effectively eliminated from a structure depends on many factors. The type of pest, the ecology near the home/structure environment, and the methods of control administered, all effect how long control can be achieved. For instance, if the ecological factors contributing to pest activity of the area near a structure can be modified to reduce a pest population, control can be maintained almost in perpetuity. If however, a chemical pesticide is the only method used for control, control will only last as long as the material applied remains in place and active. For natural or synthetic pesticides this active lifetime can be as short as a few seconds or as long as several years depending on the formulation, active ingredients, application method, etc.