Odour plumes in the wild are spatially complex and rapidly fluctuating structures carried by turbulent airflows^1,2,3,4. To successfully navigate plumes in search of food and mates, insects must extract and integrate multiple features of the odour signal, including odour identity⁵, intensity⁶ and timing^{6,7,8,9,10,11,12}. Effective navigation requires balancing these multiple streams of olfactory information and integrating them with other sensory inputs, including mechanosensory and visual cues^9,12,13. Studies dating back a century have indicated that, of these many sensory inputs, the wind provides the main directional cue in turbulent plumes, leading to the longstanding model of insect odour navigation as odour-elicited upwind motion^{6,8,9,10,11,12,14,15}. Here we show that Drosophila melanogaster shape their navigational decisions using an additional directional cue—the direction of motion of odours—which they detect using temporal correlations in the odour signal between their two antennae. Using a high-resolution virtual-reality paradigm to deliver spatiotemporally complex fictive odours to freely walking flies, we demonstrate that such odour-direction sensing involves algorithms analogous to those in visual-direction sensing¹⁶. Combining simulations, theory and experiments, we show that odour motion contains valuable directional information that is absent from the airflow alone, and that both Drosophila and virtual agents are aided by that information in navigating naturalistic plumes. The generality of our findings suggests that odour-direction sensing may exist throughout the animal kingdom and could improve olfactory robot navigation in uncertain environments.

野外的气味羽流是空间复杂且快速波动的结构，由湍流气流^1,2,3,4携带。为了成功地导航羽毛以寻找食物和配偶，昆虫必须提取和整合气味信号的多个特征，包括气味特性⁵、强度⁶和时间^{6,7,8,9,10,11,12}。有效的导航需要平衡这些多股嗅觉信息流，并将它们与其他感官输入相结合，包括机械感觉和视觉线索^9,12,13. 一个世纪前的研究表明，在这些许多感官输入中，风提供了湍流羽流的主要方向线索，导致了昆虫气味导航的长期模型作为气味引发的逆风运动^{6,8,9,10,11 ,12,14,15}。在这里，我们展示了Drosophila melanogaster使用额外的方向提示（气味的运动方向）来塑造它们的导航决策，它们使用两个触角之间的气味信号中的时间相关性来检测。使用高分辨率虚拟现实范例向自由行走的苍蝇传递时空复杂的虚构气味，我们证明这种气味方向感测涉及类似于视觉方向感测的算法¹⁶. 结合模拟、理论和实验，我们表明气味运动包含有价值的方向信息，而这些信息仅在气流中是不存在的，并且果蝇和虚拟代理在导航自然羽流时都得到了该信息的帮助。我们研究结果的普遍性表明，气味方向感应可能存在于整个动物界，并且可以改善不确定环境中的嗅觉机器人导航。