Your grandmother's insistence that you receive more bug bites because you're 'sweeter' may not be that far-fetched after all, according to pioneering research from Virginia Tech scientists.

A new shows that mosquitoes can rapidly learn and remember the smells of hosts and that dopamine is a key mediator of this process. Mosquitoes use this information and incorporate it with other stimuli to develop preferences for a particular vertebrate host species, and, within that population, certain individuals.

However, the study also proved that even if an individual is deemed delicious-smelling, a mosquito's preference can shift if that person's smell is associated with an unpleasant sensation. Hosts who swat at mosquitoes or perform other defensive behaviors may be abandoned, no matter how sweet.

Mosquitoes exhibit a trait known as aversive learning by training female Aedes aegypti mosquitoes to associate odors (including human body odors) with unpleasant shocks and vibrations.

Twenty-four hours later, the same mosquitoes were assessed in a Y-maze olfactometer in which they had to fly upwind and choose between the once-preferred human body odor and a control odor. The mosquitoes avoided the human body odor, suggesting that they had been successfully trained.

By taking a multidisciplinary approach and using cutting-edge techniques, including CRISPR gene editing and RNAi, the scientists were also able to identify that dopamine is a key mediator of aversive learning in mosquitoes.