Many symptoms are mistakenly diagnosed as head lice. Dandruff, gobs of hairspray and even small insects like aphids that have been blown into the hair on a windy day have all sent panicky parents to the pediatrician for treatment. The only foolproof diagnosis for pediculosis (a head lice infestation) is to catch sight of the elusive bugs, but look for these signs as well: Persistent scratching of the scalp Pink rash behind the ears and at the nape of the neck, resembling an allergic reaction Tiny lice eggs (called “nits”) on the hair shafts, close to the scalp, that cannot be brushed off The presence of tiny light brown bugs (the size of a sesame seed)