R.I.P Fleas triple action formula works instantly to stop fleas & house dust mites. R.I.P Fleas contains Methoprenea, a compound which mimics the insect juvenile hormone & disrupts the development of flea eggs & larvae in the environment. In real house studies methoprene has been shown to be a safe & effective way to control flea development for 12 months. Methoprene has the advantage of being highly fluid at room temperature allowing it to spread evenly & deeply into the carpet pile. R.I.P. Fleas also contains Permethrin, a potent insecticide with powerful contact action. It is light stable & is the first household synthetic pyrethroid insecticide authorised for the prevention of pests. It has a lethal effect on insects but due to it`s chemical structure it has a low toxicity to most mammals & is ideal for the control & prevention of household insects. Lastly, R.I.P. Fleas contain Bioallethrin. Although bioall