Repellents are ALWAYS EFFECTIVE. The majority of spray and spread-on skin repellents for mosquitoes and ticks contain DEET as their active ingredient, but some people find it unpleasant because it stains clothing, irritates skin, and may be harmful to use on children or in high enough concentrations (above 20 percent). Nevertheless, repellents are always effective. There are safer substitutes available, such the oil of lemon eucalyptus found in REPEL, which a recent Consumer Reports research found to be equally effective as DEET. Tick repellents that spray on may not be as effective since ticks may be able to evade the repellent depending on where they attach themselves to your body. One simple-to-use tick repellent that provides exceptional protection when sprayed on shoes and clothing is permethrin. Ticks are successfully repelled by permethrin, which works best when applied on clothing rather than skin. Its effectiveness lasts for four to six laundry cycles. If you mail your own clothing to certain companies, they will pre-treat it with Permethrin; treatments last up to 70 washings. Just keep in mind that there are several permethrin formulations available, including ones for use in gardens and farms. For personal protection, just use the formulation.