Triggering and persistence of trail-laying in foragers of the ant Lasius niger.

In the ant Lasius niger, the ability to ingest their own desired volume is the key criterion that rules the recruiting behaviour of scouts. This volume acts as a threshold triggering the trail-laying response of foragers. In this paper, we show that this desired volume is specific to each individual and is kept constant over successive trips to a food source. This individual specificity contrasts with the variability of all individual desired volumes within the colony. In this study, it is also shown that, among L. niger foragers, 14% never participate in the formation of the chemical pathway and never lay a trail over successive trips. Among the others foragers, interindividual differences in the persistence of trail-laying behaviour over successive trips are observed but do not rely on an individual specialisation, in which some ants would lay a trail more frequently and persistently than other scouts. We discuss how an individual in the foraging behaviour can play an essential role in the regulation of food retrieval dynamics.