I find it so amazing that the baby head lice, called nymphs, change color to match the color of the hair they live on. That means that on blonde hair lice actually appear lighter than on dark hair. Also, when lice are sucking their bloodmeal, they squirt a special liquid with anesthetic properties into our scalp so that we cannot feel the wound. It is only later, when we begin to experience lice symptoms such as itchiness that we realize that parasites are living on our head.