Feb. 2, 2016 -- They’re tiny. They attack with supreme stealth, biting in full daylight with no buzz and no sting. And they carry viruses that can be lethal to their preferred food source: us.

The Aedes aegypti, or yellow fever mosquito, killed more soldiers than guns did during the Spanish-American War. And now these black-and-white striped femme fatales -- only the females suck blood -- are causing misery through Central and South America as they pass the viruses that cause dengue fever, yellow fever, chikungunya and now Zika virus disease from person to person.

Their ancestors lived in the forest where they fed on all manner of warm-blooded creatures, but some time in recent history -- no one is sure exactly when -- the modern Aedesmosquito developed a preference for just one animal -- humans.

“They only live in association with humans. And they have all these physical and behavior adaptations to do it,” says Carolyn McBride, PhD. She’s an assistant professor of ecology and evolutionary biology at Princeton University who specializes in Aedes aegypti.

“They have an amazing ability to recognize human odor,” McBride says. “You can put on a lab glove and cut a little hole in the back so that just an inch of skin is exposed, and they’ll find it.”