Flies, Clark and Emonet concluded, must sense the motion of odor packets, as Emonet calls discrete clumps of odor molecules. Think about this for a second: When you smell the neighbor’s barbecue, can you tell whether the smoke particles passing your nose are traveling from left to right, or right to left? It’s not obvious. But a fly can tell — and olfaction researchers have previously overlooked this possibility.

— Read more in Scientists Are Trying to Figure Out How Animals Follow a Scent to Its Source at Smithsonian.

Flying insects, such as moths in search of a mate, adopt a “cast-and-surge” strategy, which is a form of anemotaxis, or response based on air currents. When a male moth detects a female’s pheromones, he will immediately start flying upwind, assuming there is a wind. If he loses the scent — which probably will happen, especially when he is far away from the female — he will then start “casting” from side to side in the wind. When he finds the plume again, he will resume flying upwind (the “surge”) and repeat this behavior until he sees the female.

— Read more in How animals follow their nose at Knowable Magazine.

Horses are able to discriminate between human odors produced in times of fear and joy, researchers in France report.

The findings, reported in the journal Scientific Reports, indicate that smell can be added to hearing and vision as senses through which horses can perceive human emotions.

— Read more in at Horses show ability to discriminate between human odors of fear and joy at Horsetalk.

Biologists recently discovered the first airborne pheromone produced by tsetse flies. The finding, reported in Science, promises new control methods for the biting flies, which have a long history of spreading devastating diseases across Sub-Saharan Africa.

“The best way of controlling these horrible diseases is by controlling the flies,” says senior author John Carlson, a neuroscientist at Yale University in New Haven, CT. Traps baited with cow urine are the current mainstay of tsetse control. Adding fly pheromones to the traps could lure more tsetse.

— Read more in The perfume of the tsetse fly opens new doors to disease control at PNAS.