The Tsetse Fly: A Unique but Deadly Insect (image) KU Leuven Share Print E-Mail Caption The tsetse fly is quite unique in the insect world: it feeds exclusively on the blood of humans and animals, gives birth to live young and provides nutrition to its young by lactation. But in the invertebrate world, it's a killer: its bite can transfer the parasite that causes sleeping sickness. If left untreated, the disease is fatal. Credit Geoffrey M. Attardo, Research Scientist, Yale School of Public Health Usage Restrictions May be used with the credit: Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.