Tsetse fly feeding on human blood

Photograph of a tsetse fly (Glossina) feeding on mammalian blood. Tsetse flies are blood sucking insects and are vectors of African trypanosomiasis (sleeping sickness) in man and of nagana in cattle, horses and other livestock. They carry the parasite Trypanosoma brucei and can infect humans and animals with it when biting them to feed on their blood.