Lice Infestation / Lice Life Cycle
Head lice is primarily spread by head to head contact with an individual already infested with lice and can live on any human with hair. Lice infestation starts with at least one male and one female louse invading your hair. Yes it does take two!
An adult female louse can lay between 4 and 7 eggs a day. The eggs are protected by the nit casing and attached to individual hair strands with a strong, waterproof glue. The eggs/nits will typically be placed 1/8-1 inch away from your scalp because they need the heat from your head in order to incubate. The lice eggs will vary in color from yellowish/tan, tan or brown and looks like a tear shaped speck stuck to the hair. If it is all white, then it is an empty nit and has already hatched. The eggs/nits are about the size of a poppy seed.
The lice eggs are attached well enough to the hair that they will withstand most everyday activities; Washing, brushing, styling, swimming... and due to the robust shell of the nit/egg many lice treatments do not have a high efficiency rate at killing them. This includes pesticides, oils, mayonnaise, vinegar and even hair dye.
7-10 days after an egg is laid, a nymph will hatch. Nymphs are very small and like to stay close to the scalp were the feed. Nymphs and adult lice are parasites and they do feed on our blood. Nymphs will spend 7-10 days growing into an adult, at which stage they can reproduce. An adult is about the size of a sesame seed and has six legs. The color of the bug varies from beige to gray and may appear darker after feeding. Because adult lice travel farther along the hair than the nymphs, they are more susceptible to falling off the hair, or climbing onto another head through hair to hair contact. An adult louse lives up to 30 days.