Lice are tiny, wingless, seed-like bugs that live on the scalp and feed off your blood. The first sign you may have lice is an itch that won’t go away. When you’re scratching, the lice have been living in your hair for a couple of weeks. When the lice bite, their saliva gets into the person’s blood. The saliva can cause an allergic reaction in the scalp, making it itchy. Studies suggest that only half of the population is allergic to lice saliva, so not everyone infected will be itchy. Head lice need to feed off blood several times a day. They gravitate toward specific areas of the body to feed. This is usually behind the ears and closer to the neck. Other skin conditions — such as eczema, dandruff, sensitivities, and allergies — can also cause itching. To be sure your child has lice, look for small white or yellowish particles called nits. If these nits don’t slide off when you brush them, it’s probably head lice. The nits are the lice eggs. If they aren’t removed, they can hatch and start an infection all over again. Since not everyone with lice itches, it’s a good idea to do head checks periodically to look for nits and live lice.