Although mosquitoes seem mindless and simple, they may be a bit smarter and more astute than previously thought. One of the main ways to repel mosquitoes is by using an effective repellent, but a study published in May 2026 found that they can associate common ingredients in these products with tasty food. The study, published in the Journal of Experimental Biology, examined the response of Aedes aegypti mosquitoes to DEET exposure during a blood and sugar meal in a laboratory setting. Aedes aegypti, also known as the yellow fever mosquito, is an invasive species common in the southern United States and is known for its aggressive bites and disease transmission. Surprisingly, the insects studied appeared to remember that the presence of DEET indicates the proximity of tasty blood. While this doesn't mean that repellents containing DEET don't work, it does say something about how mosquitoes respond to repellents.
Using a repellent containing DEET is one of the most effective methods for preventing mosquito bites and was thought to work by repelling mosquitoes with an odor they dislike. Professor Claudio Lazzari of the University of Tours (France), one of the study's authors, told The Guardian how these pests react to repellents differently than expected. "It was long thought that repellents worked solely through their chemical properties, either by being toxic or unpleasant to mosquitoes and repelling them, or by blocking their ability to detect humans," Lazzari explained. "However, our results show that this response can change with experience.".
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How does DEET affect mosquitoes and how to use repellents safely.
Mosquitoes fly around the backyard — Tsyb_oleg/Getty Images
This study doesn't test the effectiveness of DEET, but rather the ability of mosquitoes to learn and adapt to repellents. As The Guardian reports, 60% laboratory mosquitoes, trained to associate DEET with blood, showed a bite response to the chemical's scent, even when no blood was present. The insects' response demonstrated that they could remember that the scent of DEET is associated with blood and learned not to avoid the chemical, something they hadn't done before.
Because this study was conducted in a controlled environment with a specific mosquito species, the behavior of these pests in the wild will likely vary depending on a number of factors. However, the findings suggest that regular application of insect repellent may be crucial to the effective use of DEET-based repellents. Clement Vinauger, co-author of the study and an associate professor at Virginia Tech University, explained the everyday implications of these findings to Virginia Tech News. "If someone applies DEET and its concentration decreases over time, but the mosquito continues to feed, the insect may begin to associate that scent with reward," Vinauger said. "This is a possibility we should seriously consider when thinking about how repellents are used in the real world." While you can try homemade sprays and repellents, DEET still provides essential protection if you reapply it repeatedly. Winauger suggested that frequently reapplying insect spray would likely provide better protection than spraying a large amount at once.
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Read the original article on Hunker.