They’re very tiny -- about the size of a pinhead. They’re hard to see. The oval-shaped eggs often look yellow or white but may be the same color as your hair. They stick like glue to the end of each hair closest to the scalp and are hard to remove. You may confuse them with dandruff or flakes from hair spray build-up. Head lice nits usually hatch in 8 to 9 days. When they do, they leave behind clear shells, which remain stuck to the hair shaft.