The tsetse fly lives in nearly in sub-Saharan Africa (mostly wet tropical forest) and many parts of this large area is fertile land that is left uncultivated—a so-called green desert not used by humans and cattle. Most of the 37 countries infested with tsetse are poor, debt-ridden and underdeveloped. Of the 39 tsetse-infested countries, 32 are low-income, food-deficit countries, 29 are least developed countries, and 30 are among the 40 most heavily indebted poor countries. Eradicating the tsetse and trypanosomiasis (T&T) problem would allow rural Africans to use these areas for animal husbandry or the cultivation of crops and hence increase food production. Only 45 million cattle, of 172 million present in sub-Saharan Africa, are kept in tsetse-infested areas but are often forced into fragile ecosystems like highlands or the semiarid Sahel zone, which increases overgrazing and overuse of land for food production.