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- Ectoparasites that cause an infestation rather than infection.
- Lice live on human hosts by blood meals after piercing skin and injecting saliva that then causes pruritus.
- Lice can survive away from the human host for up to 10 days, after which time they die of starvation.
- 3 species infests humans:
- Phthirus pubis (crab louse, pubic louse)
- Pediculus humanus humanus (body louse)
- Pediculus humanus capitis (head louse)
- Life cycle: female lives 1-3 months, lays up to 300 eggs (nits). Nits hatch in 6-10 days giving rise to nymphs which become adults in 10 days.