Fipronil is a pyrazole acaricide and highly effective, broad-spectrum insecticide with potential value for the control of a wide range of pests in crop, public hygiene, amenity, and veterinary pests. It disrupts insects’ central nervous systems by blocking chloride channels that are gated by γ-aminobutyric acid (GABA) or glutamate. These receptors are weaker or non-existent in mammals.