An adult louse is about 2 mm in length. They have 6 legs with claws at the ends.
Nits may be few to numerous. They are cemented to the hair shaft. Scale from dry scalp or dandruff can look like a nit. Scale however can be moved along the hair shaft.
Lice are most often found on the back of the head and behind the ears. They can occur on eyebrows and eyelashes. Pubic lice are located in the hair in the pubic area. Scratching can lead to secondary infection with oozing and crusting.
Secondary infection of the scalp can lead to posterior cervical lymphadenopathy. Live nits will fluoresce during Woods light examination. This technique of examination is used for screening purposes in schools.