What Is a Nit? Understanding Lice Eggs and Why They’re So Hard to Remove

When it comes to head lice, nits are one of the most confusing and frustrating parts of an infestation. Parents often mistake them for dandruff, or assume that once a treatment is done, the problem is solved. In reality, nits are the reason lice can linger or return if not removed correctly.

Here’s everything you need to know about nits, their life cycle, and why professional removal is so important.

1. What Exactly Is a Nit?

A nit is the egg of a head louse.

A single female louse can lay 5–10 nits per day
Nits take 7–10 days to hatch, and it takes another 10–12 days for the baby louse to grow into an adult
Only adult lice can spread from head to head, but nits are the first step in the lice life cycle

Quick Life Cycle Overview:

Nit (egg): Glued to the hair shaft near the scalp
Nymph (baby louse): Hatches in 7–10 days
Adult louse: Grows in 10–12 days and can start laying eggs and spreading to others

2. Where Are Nits Found?

Nits are superglued to the hair shaft, typically less than ¼ inch from the scalp

They need precise heat and humidity from the scalp to incubate—like a chicken egg under a hen in a nest
This is why nits cannot hatch on a pillow, hat, hairbrush or couch

3. Why Nits (and Lice) Are Hard to Kill and Remove

Current OTC and Rx products on the market are no longer 100% ovicidal or pesticidal (able to kill all nits and lice in an infestation). Over-the-counter kits and “suffocation methods” are intended to kill live bugs and their eggs, but their efficacy is not high. Missed nits and lice must be removed manually to ensure eradication of an infestation.
Empty nit shells remain glued: Even after hatching, the shell stays attached and can move down the hair as it grows out
Professional combs matter:
- Drugstore combs are too wide to catch nits (and smaller lice)
- A professional-grade Terminator comb is designed to pull them out

Pro Tip: If just two nits are missed, the life cycle can start over, leading to reinfestation

4. What Do Nits Look Like?

The color of nits can vary depending on hair color and incubation stage:

Incubating nits: Tan or brown
On dark hair: May appear white due to the translucent shell reflecting light
Empty shells: White or clear, still glued to hair but no longer contagious

How to spot them:

On a damp white paper towel, the brown color of nits “pops” against the white background
Nits don’t flake off—you must pull them off with a comb or fingernail
Nits are a similar size and feel like a knot in a thread

5. Why Professional Removal Works Best

Lice infestations persist when nits are left behind. Even after a home treatment, if you skip a professional check:

Empty nit shells can stay in the hair, causing worry and confusion
Live nits can hatch and start the entire cycle over

At Minnesota Lice Lady, we use professional-grade tools and trained techniques to ensure every nit is removed—giving families peace of mind and helping prevent reinfestation.