An isoxazoline ectoparasiticide; selectively inhibits binding of EBOB, a GABA channel blocker, to housefly head membranes (IC50 = 455 pM versus >10 μM in rat membranes); blocks GABA- and glutamate-induced chloride currents in Xenopus oocytes expressing housefly MdGBCl or MdGluCl channels (IC50s = 5.32 and 79.9 nM, respectively); has insecticidal and acaricidal activity at concentrations of 0.0000012 to 1 ppm