The feeding habits of 15 species of Glossina have been studied by the identification of their blood meals. Representative samples of the blood meals from each of these species of tsetse fly and from different habitats were collected and 22 640 blood meals were identified. The feeding patterns are characteristic for each species of tsetse fly and do not appear to depend entirely on the availability of different hosts, suggesting that the feeding habits of Glossina are genetically determined. However, a broad grouping can be made into five categories: species feeding mainly on suids, those feeding on suids and bovids, those feeding mainly on bovids, those feeding mainly on mammals other than suids and bovids, and those feeding on most available hosts and on man.The possibility of control by selective elimination of the main hosts of these groups is discussed.