Learning behaviour is consistent across time and tasks in Formica fusca ants

Abstract

Abstract Research on interindividual behavioural and cognitive variability has gained momentum over the last few decades. Most studies focused on vertebrates, revealing that individual cognitive performance can be stable across time and tasks and linked to other behavioural traits. Invertebrates, including social insects, have received far less attention despite evidence of interindividual behavioural variability. Here we evaluated the consistency of individual learning behaviour across time and tasks in Formica fusca ants. First, we measured the repeatability over time of exploratory activity (open-field) and learning behaviour in an olfactory discriminative conditioning task at the individual level (Experiment 1). Then, we investigated the consistency of individual behavioural response across two learning tasks (discriminative and reversal learning) and the relationship between exploratory activity and learning (Experiment 2). We show that ants’ behaviour in a learning task is stable over time and that ants can reverse odorant–reward contingencies, providing the first evidence of individual-level reversal learning in ants. Individual learning behaviour in the discrimination task was positively correlated with learning behaviour in the reversal task. However, exploratory activity was not associated to ants’ behaviour in the learning tasks. Our results expand the limited body of evidence for stable cognitive traits and cross-task consistency in invertebrate learning.