Understanding how lice survive can help reduce some of the fear and anxiety associated with an outbreak.
When someone in the family has lice, there is a tendency to panic.
Dealing with head lice can be stressful and time-consuming, primarily because people don’t tend to talk about how to treat head lice until they are dealing with it.
Lice are parasitic insects. This means that lice survive by having some kind of host to provide an environment where they can survive and propagate.
Head lice have evolved with humans for hundreds of thousands of years, forming a parasitic relationship with us to the point where now the only environment lice can live for longer than 48 hours is on a human scalp with hair.
The hair is their home, and the scalp is where they get food. They have developed six claws designed specifically to attach to human hairs close to the scalp where the lice can feed on blood.
Even if someone has a shaved head, they can still get lice if they have at least an eighth of an inch of hair.
Life of a louse
The life of a louse (singular for lice) starts as an egg or nit. Female lice lay approximately three to five eggs per day.
Nits are tan or greyish in colour and are about one millimetre long and are attached to the hair shaft with a glue-like surface. They are very difficult to see and remove.
After seven to 10 days the nits hatch and begin life as immature nymphs. After about 10 days, the nymph becomes an adult louse.
A louse survives by eating several times a day. They move onto the scalp and pierce it to draw blood.
Each louse needs a can’t live without a human host for more than 48 hours. This is important to know when dealing with an infestation because there are some misconceptions about how lice spread and how to respond.
They can fall on pillows, sheets, stuffed animals, and other bedding. However, it is unlikely to catch lice from this type of environment. Lice can’t live on these surfaces, or on hats, scarves, furniture, or carpet for longer than 48 hours.
They also can’t live on pets or any other animals.
The nits can’t live without a human host. The warmth of the body provides the needed heat for nits to gestate. Nits that are removed or that fall in the form of lost hair die before they hatch.
How to clear your home of lice
Cleaning your home after a lice infestation is not a complicated as you may think.
If your child has lice, you don’t need to fumigate your house or pack away anything made of fabric in plastic bags for weeks. You just need to wash the clothes the person has worn in the last 48 hours, bedding and towels and dry them in high heat (lice can live underwater for up to eight hours).
Any stuffed animals on the bed can be put in the dryer for about 30 minutes on high heat to kill any lice and eggs or put in a bag for 48 hours.
It is also important to wash any brushes or other hair accessories that may have been used by the person with lice. We recommend soaking these items in hot water (at least 130 degrees) for at least 20 to 30 minutes.
Although it is unlikely to get lice from the environment, you should also consider other places where the person with lice has put their head where hairs with lice may have fallen—hats, backpacks, car seats, etc.
Lice can’t jump or fly. They only spread by moving from one person’s hair to another person’s hair when the people are making hair-to-hair contact—either directly or through items with hair on them.
Understanding how lice survive will help ease the stress of dealing with it. If you’re unsure if you or a family member has lice, book your head screening and let a lice professional put your mind at ease.
Lice Clinics of Canada can have you lice free in just 90 minutes.