It is unnerving to think about bugs crawling around your scalp without the additional worry of them hiding in the furniture and clothing around your house. In this article we hope to put your fears to rest and address some commonly asked questions about head lice and how they get about.
First, we will explore the head lice life cycle as this will help us understand how long head lice can live when they are not on a human host.
The head lice life cycle can be separated into three stages, knowing about these stages can help you to identify what head lice looks like:
Sometimes referred to as “nits” – these tiny, oval, whitish-yellow eggs are glued to the hair shaft close to the scalp to help them hatch.1,4 Once laid, it takes on average 8 days for a louse egg to hatch, however, the hatching time can vary between 7 and 13 days.3
Are newly hatched baby lice. 1,4 Nymphs look like adult lice but are about the size of a pinhead as compared to an adult louse which is about the size of a sesame seed. 1,4 It takes around 7 to 10 days for a nymph to mature into an adult louse capable of breeding. 1,4
Adult head lice are tan to grey in colour and have six legs ending in hook-like claws, perfect for holding onto hair. 1,4 When fully grown they are about the size of a sesame seed (up to 3mm long), the female louse is slightly larger than the male. 1,4 A louse lives on average 30 to 40 days. 1,4
Head lice, as the name suggests, tend to stick exclusively to the head and scalp.1 Head lice can be found anywhere on the scalp but they also have favourite places where they like to lay their eggs such as the temples, nape of the neck and behind the ears.3 If you are worried about if you have head lice, there are a set of signs and symptoms of head lice that can indicate the presence of an infestation. If you find lice elsewhere on the body it is likely to be a different type of louse.1 There are two other types of lice that can infest humans:
Also known as “crabs” because of their crab-like shape are usually found in pubic hair. However, pubic lice can also be found underarm and leg hair, hair on the chest, abdomen and back, and facial hair, such as beards and moustaches.6
Body lice look very similar to head lice but are slightly larger in size.1 Body lice live in your clothing and bedding and travel to your skin several times a day to feed on blood.5 The most common sites for bites are around the neck, shoulders, armpits, waist and groin — places where clothing seams are most likely to touch skin. 5
Head lice cannot live for long on pillows or sheets. It is possible for a live louse that has come off a person’s head to crawl onto another human host who also puts their head on the same pillows or sheets. 8 However, the risk of catching head lice this way is very small as head lice do not like to crawl away from their host. If you are still worried about the risk of catching head lice from pillows or sheets, then vacuuming or tumble drying these items can help further reduce the risk.8
You may be wondering if you need to wash or treat your child’s teddies, dolls and another toys, but this is not necessary.8 Historically it was recommended bagging items such as stuffed animals for a number of weeks to help bring infestations under control, this is no longer necessary as we now understand the head lice cannot survive without feeding on a human host for more than 24-48 hours. 8
Remember head lice cannot swim.4 Swimming or sharing a bath with someone who has lice carries no greater risk of catching head lice. 8 When lice are in water, they go into a state of suspended animation remaining firmly locked onto the hair – literally hanging on for dear life. 8 This is how they survive shampooing, rain, seawater and swimming pools. 8 You are more likely to transmit the head lice from person to person when sharing a towel with an infested person. 8
No, you cannot catch head lice from pets.7 Head lice are very specific to humans; therefore, you cannot catch head lice from pets and pets cannot catch head lice from humans.7
For some people there is the belief that in order to eliminate head lice you must also treat the house as well as the person. When it comes to head lice there is no need to fumigate the house or throw everything inside the washing machine.8 If you want to sleep better at night without worrying about head lice crawling about your house, you can vacuum areas where an infested person is likely to have sat or lay. 8
The hook-like claws at the end of head-lice six legs are perfectly designed for holding onto hair.4 Head lice struggle to grasp other fabrics therefore the likelihood of catching head lice from helmets, hats or headphones is very small. 8 However, risk of transmission can be eliminated by making sure children do not share these items. 8
It is possible the spread head lice through the sharing of combs or hairbrushes.1 Although head lice would struggle to cling to the hard plastic or wood of the brush/comb, there is usually hair left in these items that head lice can hold onto. Catching head lice in this way would only occur if the hairbrush or comb was shared immediately after brushing an infested person’s head.1 To reduce the risk of transmission in this way you can avoid the sharing of brushes or combs or place the combs and brushes in hot water after use for 5 to 10 minutes.1
Turn your tumble dryer onto a high heat for between 15 and 30 minutes. This should be sufficient to kill and stray head lice or nits. Remember and check if the item you are tumble drying and tumble dryer safe.
While they're might be be lots of answers to how you catch head lice, the risk tends to be small. You can reduce the risk even further with the following strategies.
If you do discover head lice, do not worry, you can take some simple steps to deal with head lice.