Pubic louse (Crabs)

Natural Habitat

Found exclusively on humans, specifically in coarse hair such as pubic, armpit, chest, or facial hair (eyelashes/eyebrows).

Diet & Feeding

Strictly hematophagous; they feed exclusively on human blood multiple times a day.

Behavior Patterns

They are obligate ectoparasites that cannot jump or fly; they move by crawling from hair to hair. Females lay eggs (nits) on hair shafts. They cannot survive more than 24-48 hours off a human host.

Risks & Benefits

Risk: Causes intense itching (pruritus) and blue spots (maculae ceruleae) at feeding sites. They can cause secondary skin infections from scratching. They are typically transmitted via close physical contact. Benefit: None.

Identified on: 3/7/2026