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 Lasius niger 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核心基础，同时也决定了群体的决策过程。我们探究了引导至食物源的路径物理特性，及其对单个蚂蚁行为产生的影响之间的相互作用，是如何影响其集体决策的。我们以不同种群规模的黑毛蚁（Lasius niger）蚁群为研究对象，设置两条长度一致但几何结构不同的路径，连接蚁巢与两份等量的食物源：一条为蚁巢至食物源的直线路径，另一条则在路径中点存在135°的方向突变。两份食物源均被同时发现，但蚂蚁优先采食直线路径终点处的食物源。基于实验与理论研究结果，我们证实：直线路径上蚂蚁返回蚁巢的行进时长显著更短，这会快速形成更强的信息素痕迹（pheromone trail），正是该采食偏好产生的根源。