DEET on skin and permethrin on clothing and shoes is more effective. With the right kind of clothing and thorough permethrin treatment, any ticks that get on you will be dead before they find their way past the clothing to bite your skin. Just don't use it on skin, and keep it away from your cats. DEET can also do nasty things to clothing made from synthetic fibers, which are generally some of the best clothing choices for hiking.