My daughter has long thick hair and she had a bad case of head lice. Although I seem to have got rid of all the lice. Combination of Derbac M and a 'nitty gritty' comb. But she has loads of white dots in her hair that seem to be stuck to her hair. I have got some out and there is nothing in them, so I don't believe they are live eggs. I'm confused about what they actually are, the only thing I can find from a google search is empty head lice eggs. If they are eggs, why am I having so much trouble getting them out.