The film starts with a sheep ranch in Australia; some sheep are affected by flies which damage the skin. Sheep parasitology is described with footage of the flies in action (there is rather inappropriately rousing music in the background). Parasites damage fleece and maggots in extreme close up are shown. The maggots can cause death and sickness. The complete lifecycle is described and shown. Lice are common (there are three types which are illustrated). Their lifecycles are described. Skin scrapings are taken to detect itch mites. The solution is sheep showers; the exact method depends on the time of year and the parasite; plunge dipping is popular or shower dips. More topical methods are demonstrated.