Pediculus-capitis, also known as head lice, is a common parasitic insect that infests the human scalp. They are most commonly found in children and are spread through direct contact with an infested person or their belongings. Symptoms include itching and redness of the scalp, and nits (lice eggs) may be visible near the base of hair shafts. Treatment involves the use of specialized shampoos or combing out the lice and nits by hand. It is important to thoroughly clean and disinfect any clothing or linens that may have come in contact with an infested person to prevent reinfestation.