When I was out on my first bird watching trip last weekend, my friend was swatting at mosquitoes constantly and they seemed to ignore me completely. What’s up with that? We were both wearing jeans and dark t-shirts. Tom~ Lansing, MI
Well that’s a new question. I did a little investigating and there is evidence that suggests that you stink and your friend doesn’t, (at least to the mosquitoes). Actually the stink you produce acts as masking odor that prevents the bugs from locating your body.
In 2005, James Logan carried out the research for natural repellents from human beings against mosquitoes with John Pickett and colleagues at the University of Aberdeen. They showed that humans that don't attract mosquitoes, produce chemicals in their sweat that either acts as a natural mosquito repellent or covers up the attractive odors.
By placing the arms of volunteers in a chamber full of mosquitoes, scientist pulled out the people that were ignored by the bugs. These lucky individuals were then wrapped in a foil and their sweat was collected. (Did the volunteers know what they signed up for? Unclear.)
Now the hundreds of distinct chemical odors that the human body produces were identified and reintroduced individually to the mosquitoes to determine which were the repellent odors. About seven or eight body chemicals have been identified as potentially related to the level of attractiveness to a hungry mosquito. While two chemicals, 6-methyl-5-hepten-2-one and Geranylacetone were determined to make a significant difference in repellency in those fortunate people like you.
The next step is to reproduce these chemicals in a natural compound that can be used by all. In the mean time stand close to your friend to confuse the mosquitoes with your masking stink and tell your friend to wear long sleeves.
Thanks for the interesting question and happy bird watching!
1. The Wall Street Journal: Finding Smells That Repel
2. NewScientist: Revealed: What mosquitoes hate about humans http://www.newscientist.com/article/dn9479-revealed-what-mosquitoes-hate-about-humans.html