Supplementary_Data from Same length, different shapes: ants collectively choose a straight foraging path over a bent one

In socials insects, exploration is fundamental for the discovery of food resources and determines decision-making. We investigated how the interplay between the physical characteristics of the paths leading to food sources and the way it impacts the behaviour of individual ants affects their collective decisions. Colonies of different sizes of <i>Lasius niger</i> had access to two equal food sources through two paths of equal length but of different geometries: one was straight between the nest and the food source, and the other involved an abrupt change of direction at the midway point (135°). Both the food sources were discovered simultaneously, but the food source at the end of the straight path was preferentially exploited by ants. Based on experimental and theoretical results, we show that a significantly shorter duration of nestbound travel on the straight path, which rapidly leads to a stronger pheromone trail, is at the origin of this preference.

在社会性昆虫中，探索行为是发现食物资源的基础，同时决定了群体的决策过程。本研究探究了通往食物源的路径的物理特性，与该特性对单个蚂蚁行为的影响之间的相互作用，如何影响蚁群的集体决策。我们以不同种群规模的黑毛蚁(Lasius niger)为实验对象，它们可通过两条长度一致但几何结构不同的路径，抵达两处等量的食物源：其中一条为蚁巢与食物源间的直线通路，另一条则在中点处存在135°的急转弯。尽管两处食物源同时被蚂蚁发现，但直线通路终点处的食物源被优先取食。基于实验与理论研究结果，我们证实：蚂蚁在直线通路的回巢行进时长显著更短，这会快速形成更强的信息素痕迹(pheromone trail)，正是该觅食偏好产生的根源。