The word “tsetse” means “fly” in Tswana, and it refers to all 23 species of the fly genusGlossina. Tsetse flies feed on the blood of vertebrate animals, including humans, thereby transmitting the sleeping sickness parasite from infected to uninfected hosts. These flies bear a resemblance to normal house flies; however, they can be identified by their distinct features. All tsetse fly species have a long proboscis extending horizontally from the base of their heads. When at rest, their wings fold over their abdomens, one exactly atop the other.