Pesticide Applicator Training: General Standards SP39-W Practice Test

Repellents are products that deter pests rather than kill them. They work by emitting odors, tastes, or other cues that pests find unpleasant, so insects and even vertebrates will avoid treated areas or items. Because the effect is deterrence, not mortality, repellents are used to keep pests away rather than to eliminate them. Other pesticide types are intended to kill or inhibit organisms—herbicides target plants, fungicides target fungi, and insecticides target insects—so they don’t fit the idea of repelling. Repellent products may need reapplication as their deterrent effect fades.