Head lice is highly contagious, especially among children, as they tend to play close together. Hair lice cause irritation and constant scratching. Contrary to popular belief, lice is not an affliction of the filthy -- the pesky insects actually prefer clean hair. It's commonly spread among people, if they share combs, brushes, towels, hats or pillowcases. To kill hair lice, it takes special medication and some hard work.
Purchase an over-the-counter lice treatment. Look for the ingredient pyrethrin or permethrin. It will also contain a comb for removing nits from hair.
Apply the treatment to the hair. Follow the instructions on the box. It generally involves leaving it in the hair for a specified period of time, and rinsing it out.
Comb through the hair and manually pick out the nits. Removing the nits is necessary for killing and removing the hair lice for good. Comb through the hair, one section at a time, right after using the treatment. Continue to comb through -- removing head lice and nits -- every three days, for at least two weeks.
Wash all bed linens, clothing and towels used by the person with head lice. Wash them in hot water. Vacuum the carpets, car seats, stuffed animals, couches and chairs. This kills hair lice.