According to one study, scientists were able to train moths to associate certain smells with food. These findings may apply to other foraging insects like honeybees and fruit flies that detect food by its odor.
Researchers at Ohio State hooked moths up to tiny electrodes to monitor their neural networks and feeding behavior, and then tried to condition them to respond to different odors by giving them food, in this case, sugar water, whenever they were exposed to a certain scent.
As the moths learned that a particular odor predicted food, scientists observed a dramatic restructuring of their neural pathways. After a few exposures to the odor, the moths started sucking for the food automatically, regardless of whether they received a reward. At the same time, the moths also learned not to respond to odors that weren't associated with food.
The moths' nervous system responses changed as they learned which odor predicted food.
The next step is to study the neural networks and try to figure out how they code these changes in behavior. Once scientists understand how moths differentiate between smells, they may be able to train them to help detect smells of interest to law enforcement or the defense industry, like those of biological and chemical weapons.