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.

在群居昆虫中，探索行为是发现食物资源的核心前提，同时主导了群体决策过程。本研究探究了通往食物源的路径的物理特性，以及该特性对单个蚂蚁行为的影响二者之间的相互作用，如何影响蚁群的集体决策。实验选取不同种群规模的黑毛蚁（Lasius niger）蚁群，设置两处等量的食物源，并通过两条长度一致但几何构型不同的路径连接蚁巢与食物源：其中一条为蚁巢直达食物源的直线路径，另一条则在路径中点处存在135°的突然转向。两处食物源均被蚂蚁同时发现，但蚁群优先选择直线路径尽头的食物源进行取食。基于实验与理论研究结果，本研究证实，蚂蚁在直线路径上的返程时长显著更短，这一特性可快速形成更强的信息素轨迹，正是该取食偏好的成因。