The insecticides discussed in this chapter comprise a group of insecticides that are not covered elsewhere in this book, with the exception of fipronil which is discussed in detail in Chapter 12. The phenylpyrazoles (fipronil and ethiprole) are antagonists at the γ-aminobutyric acid A (GABAA) receptor. Indoxacarb is anoxadiazine, which exerts its insecticidal action at voltage-dependent sodium channels. Amitraz is an amidine acaricide and insecticide used on crops and farm animals and is thought to act via the octopamine receptors in insects. The mode of action of pyridalyl on insects is unclear. Unsurprisingly, in view of their disparate mode of actions in insects, the insecticides discussed in this chapter have differing toxicities in mammals.