Can ultrasound on YouTube make mosquitoes flee?

The summer has settled, and with it, the mosquitoes, sometimes vectors of diseases. To get rid of it, videos propose, on You Tube, to diffuse ultra-sounds. Put together, they can last almost a week. But apart from using your computer or the battery of your smartphone, know that they are useless. "Even good quality speakers will not broadcast ultrasound properly, most are made to human hearing sensitivity, that is, from 20 Hz to 20 KHz," explains France Info Thierry Aubin, bioacoustician and research director at CNRS. In addition, the files undergo a compression that can alter the ultrasound when uploaded to YouTube.

Ultrasonic housings

Moreover, the ultrasound boxes sold commercially to keep away mosquitoes are just as ineffective. "All publications are unanimous: these ultrasound systems have not been scientifically proven," says France Info Frédéric Darriet, medical entomologist at the Institute for Research for Development and author of Mosquitoes and men, chronicle of an announced outbreak . A study published in 2010 in The Cochrane Library indicates that mosquitoes do not react to ultra sounds, even if they are properly broadcast.

The best ways to protect against mosquitoes, remains mosquito net and repellent (based on Deet, KBR or IR3535) sprayed on skin and clothing. And if in spite of everything you find that you are bitten more than your friends or family members, there is probably an explanation. Indeed, several studies have shown that mosquitoes have their preferences for human blood. For example, research from 2004 showed that people in blood groups A and O were more likely to be bitten by mosquitoes than people in group B. According to researchers, 85% of humans secrete a chemical signal through their blood. skin that informs the mosquito about the type of blood group: they therefore refer to it to choose their prey.

Mosquitoes love the blood of athletes

Another element that may work against you: the presence of carbon dioxide in your breath, and that can attract mosquitoes 50 meters away. This explains why children, who expire less CO2 than an adult, are less bitten. But also why pregnant women attract them particularly: they expire an average of 20% more carbon dioxide and have a higher body temperature. Mosquitoes also love the blood of athletes: the presence of lactic acid, uric acid and ammonia in their sweat attracts them like a magnet.

Finally, be aware that what you wear can also make it easier for you to be spotted by mosquitoes. According to Dr. Jonathan Day, a doctor at the University of Florida, these insects would use their sight to spot their future prey and would be particularly sensitive to black, navy and red.