British researchers may have unlocked the secret of why mosquitos find some people attractive, and leave others alone.  

"What we found is that mosquitos have a keen sense of smell and when they find a smell they like, they attack," says James Logan at the Centre for Sustainable Pest and Disease Management in Harpenden, England.

Only a handful of the nearly 400 chemical excreted by the body attract the pests. "What we don't know is why some people produce the right mix of chemicals that make them a target, and why others don't," says Logan.

Logan and a team of researchers spent seven years working of the problem, approaching it from the mosquito's point of view.

Micro-probes were attached to mosquito antennae.  The insects were then put in a large chamber flooded with the scents of the  human-extracted chemicals.

 Searching For A Longer Lasting Inspect Repellent

"Now that we know what prompts mosquitos to single out individuals, we want to develop a product that will be longer lasting than what's out there now," says Logan. 

Commercial insect repellents, which contain the chemical DEET, last for several hours but can be expensive and hard to find in areas where mosquito borne diseases, such as malaria and dengue fever, are a problem.

Testing is underway in Africa and South America on small batches of repellent and talks have started about commercializing the product. But being able to purchase the natural repellent may take several years. 

The next step is to synthesize and produce the chemicals in large enough quantities.