The eggs of lice. Both head lice and pubic lice produce eggs, which they then stick to the base of hairs growing from their host’s pubic area or head. Nits are minuscule, measuring only about 0.5mm in diameter. They are light brown when first laid and white when hatched. Hatching takes place within about eight days of being laid. Louse infestations are commonly identified by the presence of the nits.