"FRONTLINE Spray is convenient, highly effective and only needs to be sprayed once a month over the body to give your pet superior flea and tick protection. This is probably the best flea/tick spray available. It does not contain the potentially toxic insecticides found in most pet store sprays. A good choice for rapid activity in severe flea infestations. It's also good to have on hand if your pet is suddenly exposed to fleas, even when your pet is already on monthly flea control like Frontine topical or Advantage."