Head lice are tiny parasites that feed on human blood and live on a person’s head, close to the scalp. They commonly transmit among young children.

Roughly 6–12 million head lice infestations occur annually in the United States among children between 3 and 11 years old.

This article explores whether head lice can affect babies, the life stages of lice, and how to prevent lice.

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Anyone can get head lice. However, in the U.S., lice are most common among elementary schoolchildren, preschool children attending a child care setting, and people living in the same household as a child with lice.

Lice primarily transmit through direct head-to-head contact, which may be common among children who play together at:

  • home
  • school
  • other group settings, such as playgrounds and slumber parties

Additionally, a 2016 study found that having a sibling with lice increases a child’s risk of getting lice. A child may get lice after interacting with a classmate. The lice may then transmit to the child’s siblings or other family members in the household. Therefore, if there are more children in the family, a child is more likely to get lice.

This means that if a baby or toddler has older siblings or spends time with other children in group settings, they may also get lice. Therefore, parents with older children with lice should also inspect their babies and toddlers for lice.

Learn more about what lice look like.

The life cycle of a head louse has three stages: nit, nymph, and adult.

Nits

Nits are lice eggs and their shell casing. Female lice can lay up to 8 nits per day. The nits are oval and 0.8 by 0.3 millimeters (mm) in size. Female lice lay nits no more than a quarter of an inch from the scalp to keep them warm. Nits are often white or dull yellow, but they may also appear to be the same color as a person’s hair.

Therefore, nits may be difficult to see. People may confuse them for scabs, dandruff, or hairspray droplets.

Nymphs

Nymphs are immature lice that hatch from nits after around 1 week. People may refer to them as “baby lice” because they resemble adult lice but are smaller, about the same size as a pinhead.

It takes nymphs up to about 2 weeks after they hatch to become adult lice.

Adult lice

Adult lice have six legs with hook-like claws and are around the same size as a sesame seed. They are tan to grayish-white but may appear darker on people with darker hair colors.

Female lice lay their first egg 1–2 days after mating. Lice need to feed on blood several times daily to survive. They may live around 32–35 days, but they can only survive up to 2 days if they fall off a person’s head.

After they mate and lay eggs, adult lice die, and a new cycle begins.

Learn more about the life cycle of lice.

Parents and caregivers may take the following steps to prevent children and other family members from getting lice:

  • Refraining from sharing brushes, combs, or other personal items such as towels, hair bands, barrettes, and bows.
  • Advising children to avoid direct head-to-head contact during playtime.
  • Disinfecting any brushes and combs someone with lice has used with at least 130°F (54.4°C) water for 5–10 minutes.
  • Refraining from lying on couches, pillows, beds, carpets, or stuffed toys that have been in contact with someone with head lice.
  • Washing all clothes, bedsheets, and other washable items a person with lice has used in the 2 days before lice treatment on a hot laundry and dryer cycle.
  • Vacuuming beds, carpets, mats, and furniture where someone with lice has sat or laid down.
  • Drycleaning pillows, stuffed toys, and other nonwashable items a person with lice has used in the 2 days before lice treatment. Alternatively, tightly seal these items in a plastic bag for 2 weeks.
  • Refraining from spraying fumigants — they are unnecessary for managing head lice and can cause harm to people.

A person should also check the hair and scalp of everyone in the household after someone has lice treatment for 2–3 weeks. Individuals with lice may need multiple treatments.

Learn more about how to prevent lice.

Head lice are common among young children and their families.

Babies may get lice from contact with their siblings or others living in the same household or other children they spend time with in different group settings. They may also get lice by sharing items such as pillows, stuffed toys, and brushes.

Parents and caregivers should check for signs of lice in their baby’s hair and can take steps to prevent lice, such as encouraging children to avoid head-to-head contact.

A healthcare professional can help people identify lice and advise which lice treatment may work best for them.