You get lice in your hair almost exclusively through direct head-to-head contact with someone who already has them. Lice cannot jump, fly, or hop. They crawl from one person’s hair to another’s when heads touch, which is why young children, who play in close physical contact, pick them up most often.
Head-to-Head Contact Is the Primary Route
Lice are crawling insects that grip individual hair strands with specialized claws. When your head touches the head of someone with lice, even briefly, a louse can crawl from their hair onto yours. This is the most common transmission route by a wide margin. Hugging, leaning together over a phone screen, sharing a pillow during a sleepover, or wrestling on the floor all create the kind of close contact lice need to move between hosts.
Once a single adult female louse reaches your scalp, she can begin laying eggs (called nits) within a day. She cements each egg to an individual hair shaft close to the scalp, where body heat helps it develop. A single louse lays several eggs per day, so an infestation can establish itself from just one or two transferred lice. You may not notice anything for weeks, since itching is an allergic reaction to louse saliva that takes time to develop.
Can You Get Lice From Hats, Brushes, or Pillows?
Shared items like hats, combs, hair ties, and pillowcases get a lot of blame, but the CDC emphasizes that direct hair-to-hair contact is the main way lice spread. Lice are adapted to cling tightly to hair, and they need human blood to survive. Once separated from a scalp, they dehydrate and die relatively quickly. A louse sitting on a hat brim or a comb is already in trouble, and it would need to make contact with your hair and successfully crawl onto it, a less likely chain of events than a simple head touch.
That said, sharing personal items isn’t zero risk. If you use someone’s brush immediately after they do and a live louse happens to be on it, transfer is possible. The practical takeaway: avoiding shared hair tools is a reasonable precaution, but it’s far less important than avoiding direct head contact with an infested person.
Swimming Pools Don’t Spread Lice
Lice survive in water by gripping hair tightly, so they’re unlikely to release from someone’s head while swimming. Chlorine at normal pool concentrations does not kill lice. The real risk at the pool is the same as anywhere else: heads touching during play. Sharing towels afterward is a minor secondary concern.
Who Gets Lice Most Often
Children between the ages of 6 and 11 have the highest infestation rates, largely because of how they interact. They sit close together in classrooms, huddle during games, and have frequent physical contact that older kids and adults tend to avoid. In one study of boarding school students, infestation peaked at 20% in the 6-to-11 age group and dropped off sharply in teenagers.
Girls are significantly more affected than boys. The same study found a 13.7% infestation rate in girls compared to just 1.1% in boys. Two factors explain most of this gap: girls tend to have longer hair, which gives lice more surface area to grab during brief contact, and girls are more likely to engage in close social behaviors like whispering, braiding each other’s hair, or taking photos cheek to cheek. Hair length itself is a clear risk factor. Students with long hair had a 15.1% infestation rate versus 4.5% for those with short hair.
Lice spread rapidly in any setting where people are in close, repeated contact. Schools, summer camps, slumber parties, and shared living spaces like dormitories all create ideal conditions.
Lice Have Nothing to Do With Cleanliness
One of the most persistent myths about lice is that they prefer dirty hair or signal poor hygiene. There is no link between how often you wash your hair and your risk of getting lice. Lice feed on blood from the scalp, not on oil, dirt, or hair product. A freshly shampooed head is just as hospitable as one that hasn’t been washed in days. Socioeconomic status, household cleanliness, and personal grooming habits make no difference. Anyone with hair can get lice.
Pets Cannot Give You Lice
Human head lice are species-specific parasites. Dogs, cats, and other household pets do not carry or spread them. The lice that infest humans (Pediculus humanus capitis) can only feed on human blood and cannot survive on animal hosts. If your child has lice, there is no need to treat or isolate your pets.
How to Reduce Your Risk
Since head-to-head contact drives nearly all transmission, prevention comes down to limiting that contact when lice are circulating in your community. Teach children to avoid touching heads during play, especially if a classmate has been sent home with lice. Keeping long hair pulled back in a braid or ponytail reduces the chance that loose strands will bridge the gap between two heads.
Avoid sharing brushes, combs, hair accessories, and hats with others, particularly during an active outbreak. If someone in your household has lice, check every family member’s scalp carefully. Look for tiny, oval nits cemented to hair shafts near the scalp, especially behind the ears and along the neckline. Early detection makes treatment faster and limits spread to others.