Generally, the first symptom of head lice is persistent itching or scratching at the back of the head or around the ears. The lice like to stay close to the head where it is warm and close to their food source, human blood. If a child is observed repeatedly scratching his or her head, check the hair shafts and scalp closely for head lice or their nits (eggs). It is important to check for head lice in good daylight with a magnifying glass. They are very difficult to see, especially in light hair.