No offence to you, but scientists have found that mosquitoes may find your feet as alluring as Limburger cheese. If that’s you, don’t fret – it doesn’t mean you’re not washing them enough. Mosquitoes are simply enchanted by certain DNA.
A UK research team recently investigated the genetic role in mosquito attraction by testing the bite appeal of 18 identical and 19 fraternal pairs of female twins. In a series of tests, 20 hungry mosquitoes were released into the end of a Y-shaped tube and allowed to choose whether to follow their noses left or right. Down either path was one twin’s hand, releasing its delicious natural odours but protected from bites behind a mesh screen. After testing all 37 twin pairs, scientists found that the identical twins had consistently more similar attraction scores than the fraternal ones did – specifically, 67 per cent of a person’s insect appeal had to do with her genes.
So what’s the deal: does DNA stink? Thankfully, no. But specific DNA does attract unique species of microbacteria to your body – and those are what mosquitoes just can’t resist.
Each of us, right now, is covered with about 100 trillion microbes, outnumbering our human DNA ten to one. Maybe weirder still: scientists believe we share only a fraction of these microbial species with one another, making our ‘microbiome’ – the world of bacteria living in and on us – unique, just like our fingerprints. In addition to producing many of the vitamins and chemicals in our blood, our microbiome is thought to be responsible for most of our distinct odours as well.
Different mosquitoes prefer different smells from different parts of the body – that’s why Anopheles gambiae (known for spreading malaria) prefers biting hands and feet, while others go right for the armpits or groin. And those smells come from chemicals produced by our microbiomes.
So the next time a group of hungry mossies swarms your cousin but leaves you bite-free, thank your DNA for the world of microscopic creatures on your skin that produce just the right smell to send the bloodsuckers reeling.
Four Ways to Make Your Microbiome Less Mosquito Friendly
- Mask it with spray Choose a repellent with DEET, lemon eucalyptus oil, icaridin or IR3535.
- Cover it with body armour Get extra protection from clothing containing permethrin, a synthetic insecticide.
- Keep it dry Mosquitoes love carbon dioxide and heat – your body emits more of each when you exercise.
- Really dry Beer alters your skin’s chemistry, luring certain mosquitoes in. (And no, scientists don’t know why yet.)