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Forget about lions, tigers, sharks and venomous snakes: The creature that kills and sickens far more people than all these fearsome predators combined is the humble mosquito. Every year, mosquito-borne illnesses kill more than a million people worldwide. Knowing what attracts them to us is important to keeping them away. We know the little bloodsuckers use pheromones to communicate with each other; but humans advertise their presence to mosquitoes in other ways.
What Pheromones Are and Do
Pheromones are chemical signals that insects and other animals send out to communicate with other members of their species, most often for purposes of reproduction. For example, when a female mosquito is ready to have the eggs she's carrying fertilized, her body releases pheromones to attract male mosquitoes, who can follow the scent to her. Some manufacturers of perfumes claim they contain pheromones, implying that members of the opposite sex will be attracted to people who buy them, but scientists aren't sure that humans give off pheromones at all, let alone what they might be.
What Attracts Mosquitoes to Humans
Only female mosquitoes bite and draw blood, because their bodies need it to make eggs. Scientists at the Agricultural Research Service, a division of the United States Department of Agriculture, say that our skin gives off more than 340 different chemical scents, some of which mosquitoes find irresistible. Socks absorb some of their favorites, the smellier the better. But researchers from the University of California at Riverside have concluded that the carbon dioxide our skin gives off first attracts the bugs' attention, and our skin scents become important after that, when the mosquitoes are searching for the best spots to bite.
Diseases Carried by Mosquitoes
Potentially, those itchy red bumps we get from mosquito bites are more than just nuisances. Mosquitoes are capable of transmitting a wide range of diseases to humans and animals, many extremely serious and sometimes fatal. Among Americans, mosquito-borne dengue fever has been reported in Texas, Hawaii and Florida. Two forms of encephalitis, St. Louis and LaCrosse, are both firmly established in different regions of the United States. In the sheer numbers of people infected, though, the West Nile virus has a commanding lead. Since 1999, when the disease first appeared in the United States, more than 37,000 people have been infected; 16,000 of them experienced serious illness and more than 1,500 died, the Centers for Disease Control and Prevention says. Since many cases go unreported, the CDC estimates that more than 3 million people, in every state except Alaska and Hawaii, have actually been infected.
How to Become Less Attractive to Mosquitoes
By adopting a two-part defense, you'll reduce the chances of getting mosquito bites. First of all, try not to attract them. The tiny vampires are drawn to scent, so use fragrance-free soaps and toiletries. Since they prefer dark clothes, wear light clothes. If they find you anyway, make yourself as unappetizing as possible by applying an EPA-registered insect repellent on your skin and clothing when you go out. The more skin you expose, the more vulnerable you'll be to mosquito bites, so long-sleeved shirts, long pants and socks will help protect you. Peak feeding times for mosquitoes are at sunset and sunrise, so either avoid going out then or be extra careful to take precautions against being bitten.
- United States Department of Agriculture: How Attractive Are You? To Mosquitoes, That Is
- UCR Today: Flight Patterns Reveal How Mosquitoes Find Hosts to Transmit Deadly Diseases
- Smithsonian Institution Encyclopedia: BugInfo: Pheromones in Insects
- Scientific American: Do Pheromones Play a Role in Our Sex Lives?
- Revista Brasileira de Entomologia: Review of Semiochemicals That Mediate the Oviposition of Mosquitoes: A Possible Sustainable Tool for the Control and Monitoring of Culicidae
- American Mosquito Control Association: Mosquito-Borne Diseases
- Clark University: Some Notes on Mosquito Natural History
- Centers for Disease Control and Prevention: West Nile Virus and Preventing Mosquito Bites
- Mount Sinai Hospital Department of Microbiology: FAQ: How Do I Avoid Mosquito Bites?
- Thomas Northcut/Photodisc/Getty Images