Natural population of the head-louse (Pediculus humanus capitis: Anoplura) on infected children in England

The louse populations of the heads of 93 infested children, 45 boys and 48 girls under 14 years of age from a northern English industrial city have been examined. The average number of lice per head was 14·8 for all children, 12·7 for boys and 16·8 for girls. The maximum population observed was 142. The majority of infestations (65%) were light with under 10 lice. Girls were more frequently heavily infested than boys. Most of the infestations, though light, must have been established at least for some weeks.