How insects find their targets in a chaotic world

Insects use a well-honed sense of smell to transmit diseases, destroy crops, and pollinate flowers — behaviors that are both beneficial and detrimental for humankind. These tasks are complicated because natural odor environments fluctuate rapidly in the wild. How do insects find their targets in a world of ever-changing signals? The lab of Yale’s Thierry Emonet found an ingenious way to track — and even predict — how insects navigate in a chaotic world. By exposing flies in darkened area to smoke from a burning stick, researchers in Emonet’s lab mimicked natural world of complex, fluctuating odor signals, allowing them to record not only the flies seemingly random movements, but also the odor signal a fly perceives during navigation.

The research is published in the journal eLife.

“When the air flow is stable and odor release is relatively constant, flies navigate in a more deterministic way,” Emonet said. “But when faced with a more complicated signal they adopt a more probabilistic strategy to control their speed and orientation and navigate toward the source.” Understanding how nature has developed strategies to navigate changing signals has technological benefits as well: it could help developers of artificial intelligence design robots to navigate environments inaccessible to humans, such as finding hidden explosives.