Study Finds 60% of Mosquitoes Learn to Seek Fading DEET as Blood Cue
Updated
Updated · TIME · May 28
Study Finds 60% of Mosquitoes Learn to Seek Fading DEET as Blood Cue
12 articles · Updated · TIME · May 28
More than 60% of mosquitoes returned to a feeding mesh when researchers reintroduced DEET alone, showing they had learned to treat the fading repellent scent as a signal of a meal.
Virginia Tech's Clément Vinauger and colleagues found the effect emerged after mosquitoes fed in DEET's presence; once the odor weakened but remained detectable, it no longer deterred them.
In hand tests, trained mosquitoes attacked both a DEET-sprayed hand and an untreated one, while untrained mosquitoes favored only the untreated hand; sugar-feeding trials showed the same learned attraction.
The study does not say DEET is ineffective, but suggests reapplying it through the day so skin concentrations stay above the level mosquitoes find aversive, alongside nets, screens and removing standing water.
If Deet can be outsmarted, what does the future of bug spray look like?
Is your insect repellent secretly teaching mosquitoes to find you?
Mosquitoes Can Learn to Associate DEET With Blood Meals: 2026 Study Reveals New Challenge for Repellent Effectiveness
Overview
A recent study published in 2026 revealed that Aedes aegypti mosquitoes can learn to associate the scent of DEET with a blood meal, using Pavlovian conditioning techniques. This marks a major shift in how scientists understand mosquito behavior, showing that mosquitoes are not just repelled by DEET but can adapt their responses based on past experiences. The research found that when mosquitoes were trained to link DEET with a rewarding blood meal, a significant number later attempted to bite when exposed to DEET alone. This discovery highlights the adaptability of mosquitoes and has important implications for future mosquito control strategies.