Sheep and goats are susceptible to a number of annoying pests, including sheep keds (ticks), lice, sheep nose bot flies, wool maggots (fleece worms), and sheep scab (mange). Swine often encounter hog lice and mange, or itch mites. Confined livestock may be plagued by house and stable flies, while animals on pasture may encounter horse flies and deer flies. Symptoms of these pests vary from minor itching and irritation to extreme annoyance and fatigue, malnutrition, and even death. Pests also can transmit diseases and cause secondary infections.