Doggles Insect Repellent Shirt, X-Small, Gray The Insect Shield Dog T-shirt is so easy to use! Pull over style shirt. Slip it over your dogs head and place your dog's legs through the arm holes and you're set for bug-free adventures with a cute sporty style! Long lasting: Repels insects through 70 launderings! Repels mosquitoes, ticks, ants, flies, chiggers, and no-see-ums. How it works: The Insect Shield T-shirt by Doggles, is made of fabric that is bonded (by magic!) to permethrin using the same EPA rated technology as that for human Insect Shield clothing. Permethrin is a man-made derivative of Chrysanthemum flower extract. Permethrins have been used in flea and tick dips, shampoos, etc for dogs for many years. We were told by the InsectShield representative that the T-shirt should repel insect for a 3' radius, so your dog's tail and head should also be protected.