The pesticide should be applied only to specific areas where the pest is likely to find harborage or a hiding place. Generally, people do not realize that strict application of the IPM process is based on economic thresholds due to damage caused by a pest. The public may have to accept more spotted or blemished apples at the market or tolerate signal weeds in the lawn as a trade-off to frequent or recurring application of toxic chemicals to the environment. Yet some insect activity, such as transmission of bubonic plague from ground squirrels to a person by the bite of a flea or the destruction of wood in a house by termites, cannot be tolerated at any level of incidence without loss in terms of human life or economic viability. The application of a pesticide to kill a pest such as a cockroach or a rat is a simple, easy action that requires nod thought or planning and usually guarantees quick results.
Pesticides appear to offer a simple solution to a vexing problem.
However, in many cases pesticides themselves become part of a complex problem of environmental assault and adverse consequences for non-target plants and animals. Finding effective alternative methods of pest control that do not use chemical pesticides or that blend pesticide application with other pest control procedures can be complicated, but IPM is a logical process and can be started with imperfect knowledge or technical expertise. Any effort that eliminates part of the pest population is a step in the right direction. The most basic concept to understand is that pests occupy an area because they obtain food, water or shelter in that area. For example, cockroaches or rats will not live where they can't hide.