The results: the most effective repellents against mosquitoes and ticks contain 25 to 30% DEET as their active ingredient. At ...

Photo: Consumer Reports In our tests against ticks, we used Cutter Sport Insect Repellent Spray, a product with 15 percent deet; Off Sportsmen Deep Woods Insect Repellent 3, an aerosol spray that ...

more commonly referred to as DEET. This molecule has been commercially available since 1957, after the United States military discovered it was an effective insect repellent. For example ...