Test rats increased their own helping behavior when they were presented with the smell of a helpful rat. Remarkably, this holds true even though they did not experience this helpful behavior themselves. Furthermore, such a 'smell of cooperation' depends on the actual activity of helping and is not connected to an individual rat.

— Dr. Nina Gerber of the University of Göttingen on the results of her research on rat behavior; read more in Research team finds effect of odor on helpfulness in rats at Phys.org.

The findings show that honeybees given food scented with odors that mimicked sunflowers supported a significant increase in sunflower crop production.

"We show that it's possible to condition honeybees to a rewarded odor inside the colony, and this experience modifies the bees' odor-guided behaviors later," says Walter Farina of Universidad de Buenos Aires, Argentina. "The most surprising and relevant result is that the foraging preferences for the target crop are so prolonged and intensive that it promoted significant increases in the crop yields."

— Read more in Scientists 'scent train' honeybees to boost sunflowers' seed production at Science Daily.

She has found, for instance, that the malaria parasite seems to alter the mosquitoes’ sense of smell so that they are even more attracted to smellier feet, swarming to worn socks like bees to a flower bed. “There is some evidence that some proteins in the head of the mosquito change somehow, and they have a role in the olfactory response of mosquitoes,” says Smallegange. It’s a devious mechanism that leads the malaria’s host to home in on potential victims, so that it can continue its life cycle in a human body.

— Dr Renate Smallegange, a medical and veterinary entomologist at Wageningen University in the Netherlands, quoted in The disgusting secrets of smelly feet at BBC.

In research published in Biosensors and Bioelectronics: X, researchers showed how they were able to hijack a locust's olfactory system to both detect and discriminate between different explosive scents—all within a few hundred milliseconds of exposure.

They were also able to optimize a previously developed biorobotic sensing system that could detect the locusts' firing neurons and convey that information in a way that told researchers about the smells the locusts were sensing.

— Read more in Researchers One Step Closer to Bomb-sniffing Cyborg Locusts at Laboratory Equipment.