Louses

Louses, also known as lice, are small, wingless parasitic insects that live on the bodies of mammals and birds. They belong to the order Phthiraptera and are obligate parasites, meaning they cannot survive without a host. There are three main types of lice that affect humans: head lice (Pediculus humanus capitis), body lice (Pediculus humanus humanus), and pubic lice (Pthirus pubis), commonly known as crabs. Head and body lice are morphologically similar and are considered subspecies of the same species. Pubic lice are distinct in their appearance and have a different host specificity.

Lice are transmitted through direct contact with an infected host. Head lice are most commonly spread through head-to-head contact, while body lice can be transmitted through sharing clothing, bedding, or towels. Pubic lice are typically spread through sexual contact. Lice feed on blood, and their bites can cause itching and skin irritation. While generally not a serious health threat, lice infestations can be uncomfortable and may lead to secondary bacterial infections if the skin becomes scratched excessively. Diagnosis is usually made by visual inspection, and treatment typically involves over-the-counter or prescription medications designed to kill lice and their eggs.