The lesser slow loris (Nycticebus pygmaeus) is a small nocturnal primate that inhabits the tropical rainforests of Cambodia, Laos, and Vietnam. It has a head–body length of 15–25 cm and a body mass of about 400 g, making it the smallest species among the slow lorises. It feeds mainly on tree resin and sap, and also consumes fruit and insects. During winter it reduces activity and relies on stored fat for survival, and its fur is known to change in shade with the seasons. It has the unusual defense of applying toxin obtained from sweat glands on its arms to its mouth. In recent years populations have declined due to use in traditional medicine and the pet trade; it is classified as Critically Endangered (IUCN Red List category IUCN 1B).