mosquito repellent, deet
The spread of West Nile virus in South Dakota has turned attention to mosquito repellents. Questions concerning available products, effectiveness, and safety, especially for children, are being raised. Most species of mosquito are most active during the evening shortly after sundown and again before sunrise. Mosquitoes are attracted to humans primarily because we produce carbon dioxide and lactic acid. Individuals vary significantly in their attractiveness to mosquitoes. In general, men are bitten more than women and adults are bitten more frequently than children. Some of us itch and scratch and raise welts and some of us barely know a mosquito was around.
Wilson, Jim, "DEET as a Mosquito Repellent:
What You Need to Know" (2004). SDSU Extension Extra Archives. 349.