Head lice have been a constant source of problems for thousands of years, and as you have discovered, they are not at all easy to get rid off. In addition, entire families often pick up the lice from any single member, since head lice can only be transferred by close social interaction, and direct head-to-head contact or shared objects such as brushes, hats, and towels. In almost all cases, it's the little ones who end up brining it home from the schoolyard. Luckily, these tiny, wingless insects do not cause any serious disease. A colony of head lice will be born, live, and die on your scalp, thriving on human blood. In fact, head lice cannot survive for more than 2 days if they are removed from your head. The population of lice is usually stronger at the back of the head and behind the ears, where the lice lay their eggs (called nits). A single female can lay up to 100 nits in her lifespan of around 20 days. These nits hatch in around two weeks, thus maintaining a constant presence of lice on your head.
This is the main reason why you are experiencing so much difficulty in getting rid of the lice. Most over-the-counter medications work well, and can kill all the adult lice. However, the nits are well-protected by their covering and can survive, only to hatch a few days later. And before you know it your family has a whole new generation of head lice! The only way to permanently win your battle against the lice is to continue treatment for at least a month. While a chemical product can be used at the start, it may not be advisable to use it over the month, since it can damage hair and the skin.
Try adding a few drops of tea tree oil to water before rinsing your hair on a daily basis. This natural wonder has an active ingredient (terpinen-4-ol) that has been shown to dislodge and kill head lice. You will also need to take some strict measures to prevent contamination from one family member to another. Use separate towels and pillows and wash these regularly. Combs and hair brushes should be sterilized by cleaning them in water that has a few drops of tea tree oil. This month-long treatment will not allow the newly hatched lice any time to create fresh eggs, thus finally ending your family's misery!
answered by M W