Scientists have discovered the reason that mosquitos switched from feeding on animals to humans: the smell of a chemical vapor on human skin.
The chemical, called sulcatone, has a unique scent that mosquitos learned to associate with food, The Independent reports.
“It was a really good evolutionary move,” said Leslie Vosshall of Rockefeller University in New York, who led the study published in the journal Nature, “We provide the ideal lifestyle for mosquitoes. We always have water around for them to breed in, we are hairless and we live in large groups.”
Researchers found that mosquitos that still feed on animals do not respond to the presence of sulcatone, but those that prefer humans are drawn to the scent.
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Write to Tessa Berenson at tessa.Rogers@time.com