- Doctors & Departments
- Conditions & Advice
- Your Visit
- Research & Innovation
Symptoms of Head Lice
Lifespan of Lice
Transmission of Head Lice: Live Lice, Not Nits
Egg (Nit): Nits are head lice eggs. They are very small, about the size of a knot in thread, hard to see, and are often confused for dandruff or hair spray droplets. Nits are laid by the adult female at the base of the hair shaft nearest the scalp. They are firmly attached to the hair shaft. They are oval and usually yellow to white. Nits take about 1 week to hatch. Eggs that are likely to hatch are usually located within 1/4 inch of the scalp.
Nymph: The nit hatches into a baby louse called a nymph. It looks like an adult head louse, but is smaller. Nymphs mature into adults about 7 days after hatching. To live, the nymph must feed on blood.
Adult: The adult louse is about the size of a sesame seed, has six legs, and is tan to greyish-white. In persons with dark hair, the adult louse will look darker. Females, which are usually larger than the males, lay eggs. Adult lice can live up to 30 days on a person's head. To live, adult lice need to feed on blood. If the louse falls off a person, it dies within 2 days.
This shows head lice nits in the hair. Nits are the eggs of head lice which stick to the hair.
This shows an allergic reaction to the saliva of a louse (a louse is one lice). It makes the skin itchy and red.
The information contained in these topics is not intended nor implied to be a substitute for professional medical advice, it is provided for educational purposes only. You assume full responsibility for how you choose to use this information.
Always seek the advice of your physician or other qualified healthcare provider before starting any new treatment or discontinuing an existing treatment. Talk with your healthcare provider about any questions you may have regarding a medical condition. Nothing contained in these topics is intended to be used for medical diagnosis or treatment.
If you think that your child is having a medical emergency, call 911 or the number for the local emergency ambulance service NOW!
And when in doubt, call your child's doctor NOW or go to the closest emergency department.
The search for nearby emergency and urgent care facilities is based upon Google search parameters. You will get results based on how facilities manage their website information.
By using this website, you accept the information provided herein "AS IS." Neither publishers nor the providers of the information contained herein will have any liability to you arising out of your use of the information contained herein or make any expressed or implied warranty regarding the accuracy, content, completeness, reliability, or efficacy of the information contained within this website.
Certified Pediatric Nurse Practitioner
Certified Family Nurse Practitioner