DEET Blocks Bugs From Smelling Humans as "Food"

Brian Handwerk
for National Geographic News
March 13, 2008

The popular bug spray known as DEET blocks insects from picking up the smells on humans that would otherwise register as "food," a new study says.

The finding could help solve the 50-year-old mystery of exactly how the powerful human-made repellent keeps mosquitoes and other pests at bay.

Many consumers have long believed that strongly scented DEET also smells bad to insects and causes them to steer clear.

But according to the new research, DEET temporarily destroys an insect's sense of smell by hindering the function of certain odor receptors.

"From far away they start smelling you," said study co-author Leslie Vosshall of the Rockefeller University in New York City.

"Then they encounter a cloud of DEET and their olfactory system is jammed and they can't find you."

Powerful and Mysterious

Scientists at the U.S. Department of Agriculture invented DEET in 1958, but at the time no one fully understood how it worked.

"They found it more or less by trial and error," Vosshall said.

"I assume they found compounds off the shelf and tested them for their ability to make mosquitoes go away. Then they tinkered with molecules to make them safer and more effective."

(Related news: "Frog 'Juice' May Be Next Big Bug Repellent" [July 24, 2006].)

Morflex, Inc., the world's largest DEET manufacturer, estimates that about 200 million people around the globe use the repellent each year.

Continued on Next Page >>


SOURCES AND RELATED WEB SITES

ADVERTISEMENT

NATIONAL GEOGRAPHIC'S PHOTO OF THE DAY

NEWS FEEDS     After installing a news reader, click on this icon to download National Geographic News's XML/RSS feed.   After installing a news reader, click on this icon to download National Geographic News's XML/RSS feed.

Get our news delivered directly to your desktop—free.
How to Use XML or RSS

National Geographic Daily News To-Go

Listen to your favorite National Geographic news daily, anytime, anywhere from your mobile phone. No wires or syncing. Download Stitcher free today.
Click here to get 12 months of National Geographic Magazine for $15.