Headlice and eggs

Both Pediculus humanus humanus and Pediculus humanus capitis are ectoparisites of humans. Lice feed after piercing the skin and injecting their saliva (Guenther 2012). The injection of their saliva will often cause pruritus, which is the sensation that causes the host to itch the infected area. Both species of Pediculus humanus lay their eggs in their habitat. Pediculus humanus humanus will often lay eggs in the seams of clothing, while Pediculus humanus capitis will lay their eggs on human hair shafts. The overcrowding in an area encourages both species to spread to other hosts. They can spread by human contact with each other in Pediculus humanus capitis or through the sharing of clothes in Pediculus humanus humanus (Guenther 2012).