Mosquito control is serious business in Harris County, Texas.
The county, which includes Houston, stretches across 1,777 square miles and is the third most populous county in the U.S. The area's warm, muggy climate and snaking system of bayous provide an ideal habitat for mosquitoes — and the diseases they carry.
The county began battling mosquitoes in earnest in 1965, after an outbreak of St. Louis encephalitis. Hundreds of people contracted the virus and 32 died.