She attaches each egg with a cement-like material that does not wash out. If the louse mated, her eggs may develop during the next 9 days.The eggs do not grow, move or cause any health problems. Once developed, the young louse (called a nymph) breaks out of the egg, crawls on the hair and leaves behind the now empty eggshell.
The empty egg will never produce another louse, but it will remain glued to the hair until it is broken or cut off.
The nymph will grow in size and shed its skin every few days until it has matured to become an adult. Only the adult female can lay eggs