Aedes aegypti mosquitoes float in a mosquito cage at a laboratory in Cucuta, Colombia, Thursday, Feb. 11, 2016. The laboratory, run by the Health Institute of Norte de Santander, the Colombian state that's been hardest hit by the Zika virus, keeps samples of mosquitoes collected from different areas to study their resistance to insecticide and adjust the formula for fumigation campaigns. The Aedes aegypti mosquito is the vector that transmits the Zika virus, and also dengue and chikunguna. (AP Photo/Ricardo Mazalan)