Unless you're a vampire from the Twilight series, being known as a bloodsucker is never a good thing. Native to Africa and almost exclusively found in woodland areas, tsetse flies transmit what is commonly known as "human sleeping sickness." Although the flies are found in all parts of the continent, human sleeping sickness almost always occurs in sub-Saharan Africa. The illness first starts with fever, headaches, joint pains and itching and can develop into confusion, sensory disturbances, poor coordination and disturbance of the sleep cycle. If left untreated, it can be fatal. While there have been several epidemics of human sleeping sickness in Africa since the early 20th century, the number of cases reported in 2009 dropped below 10,000 for the first time in 50 years.