Lice Preventive hair bands with 100% natural tea tree oils and rosemary with a pleasant and refreshing fragrance. We like the smell, but lice DON’T. The Lice Preventive Hair Bands are infused with these essential oils, which evaporate through the effect of heat released from the head. Lice Preventive Hair Bands is a 100 % natural and free of parabens. It may be used on children ages 3 and up.