Head Lice Life Cycle

Meet A Louse: From Nit to Adult

The lice's life cycle has three distinct stages. These include nit, nymph and adult. (Got to admit they have two cute names there!).

PRESSURE SORES STAGES

It takes approximately one month for a louse to go from one egg stage to the next. The egg of a head louse is called a nit. The adult female lice lay the eggs. And they lay them on the shaft of your hair using what can only be described as a strong "cement." These eggs are located as close to possible to the scalp. Why? Because your body heat is required for incubation. Without your body warmth, they would never hatch. In fact, nits are usually found within 6 mm of the scalp.

The size of a nit is small -- actually tiny. They are about 0.8 mm by 0.3 mm. And believe it or not, even at this tiny size, scientists tell us that a nit is an oval shape! Nits can be yellow or white.

From Nit to Nymph

The egg stage lasts six to nine days before they hatch. Once they hatch, they release the nymph. The nit shell itself, though, remains attached to the hair and then turns a dull yellow color.

The appearance of the nymph is very much like a louse in miniature. As the nymph grows, it eventually outgrows its exoskeleton and sheds it. An exoskeleton, by the way, is the hard outer structure many insects have. It's much like our bones -- or skeleton -- but on the outside. It's very useful in protecting them.

In fact, a nymph sheds his exoskeleton three times before it's considered an adult.

The size of these middle stage lice varies, but usually they're seen as about the size of a pin head. In this stage, the lice take on a yellow to rust colored shading.

Nymphs stay close to the scalp, and you can usually find them behind the ears and at your neckline. The nymphs, however, do not stay nymphs for very long. They usually grow into adult lice within seven days.

From Nymph to Louse

That brings us to the adult louse. Once fully grown the louse eats about five times a day. He does this by piercing your skin with his claws, injecting his saliva -- which is quite irritating to you (as you are well aware!). After he injects his claw, he then sucks your blood.

Unlike ticks, lice do not become engorged with the fluid but they do change color. After feeding they appear more rust-colored.

Through all of this lice, hang onto your hair with their hook-like claws. These claws are found at the end of each of their six legs. Despite the fact that lice are wingless and can't jump, they travel quickly.

Believe it or not, the adult louse can live up to 30 days on your head. During this time, an adult female louse -- which is usually larger than her mail counterpart -- can lay up to 8 nits per day.

Head Lice Life Cycle

PRESSURE SORES STAGES