Animal Comparative Economics Laboratory, Institute of Zoology and Evolutionary Biology, University of Regensburg, 93053 Regensburg, Germany.
Faculty of Medicine, University Hospital Regensburg, 93042 Regensburg, Germany.
J R Soc Interface. 2020 Feb;17(163):20190661. doi: 10.1098/rsif.2019.0661. Epub 2020 Feb 26.
In order to make effective collective decisions, ants lay pheromone trails to lead nest-mates to acceptable food sources. The strength of a trail informs other ants about the quality of a food source, allowing colonies to exploit the most profitable resources. However, recruiting too many ants to a single food source can lead to over-exploitation, queuing, and thus decreased food intake for the colony. The nonlinear nature of pheromonal recruitment can also lead colonies to become trapped in suboptimal decisions, if the environment changes. Negative feedback systems can ameliorate these problems. We investigated a potential source of negative feedback: whether the presence of nest-mates makes food sources more or less attractive. workers were trained to food sources of identical quality, scented with different odours. Ants fed alone at one odour. At the other odour ants fed either with other feeding nest-mates, or with dummy ants (black surface lipid-coated glass beads). Ants tended to avoid food sources at which other nest-mates were present. They also deposited less pheromone to occupied food sources, suggesting an active avoidance behaviour, and potentiating negative feedback. This effect may prevent crowding at a single food source when other profitable food sources are available elsewhere, leading to a higher collective food intake. It could also potentially protect colonies from becoming trapped in local feeding optima. However, ants did not avoid the food associated with dummy ants, suggesting that surface lipids and static visual cues alone may not be sufficient for nest-mate recognition in this context.
为了做出有效的集体决策，蚂蚁会释放信息素来引导巢内同伴前往可接受的食物源。信息素痕迹的强度可以让其他蚂蚁了解食物源的质量，从而使蚁群能够利用最有利可图的资源。然而，将太多蚂蚁招募到单一食物源可能会导致过度开发、排队，从而减少蚁群的食物摄入量。信息素招募的非线性性质也可能导致蚁群陷入次优决策，如果环境发生变化的话。负反馈系统可以改善这些问题。我们研究了一种潜在的负反馈来源：巢内同伴的存在是否会使食物源更具吸引力或吸引力降低。 工蚁被训练到具有相同质量的食物源，这些食物源散发出不同的气味。蚂蚁单独在一种气味下进食。而在另一种气味下，蚂蚁可以与其他正在进食的巢内同伴一起进食，或者与没有生命的假蚂蚁（涂有黑色表面脂质的玻璃珠）一起进食。蚂蚁往往会避开有其他巢内同伴存在的食物源。它们也会减少在被占据的食物源上的信息素沉积，这表明它们有一种主动回避的行为，从而增强了负反馈。这种效应可能会防止在其他有利可图的食物源存在的情况下，单个食物源上出现过度拥挤的情况，从而提高集体食物摄入量。它还可能潜在地保护蚁群免受陷入局部觅食最优的情况。然而，蚂蚁不会避开与假蚂蚁相关的食物，这表明在这种情况下，表面脂质和静态视觉线索本身可能不足以进行巢内同伴识别。
