Dynamic pathogen detection and social feedback shape collective hygiene in ants

Abstract

Cooperative disease defense emerges as group-level collective behavior, yet how group members make the underlying individual decisions is poorly understood. Using garden ants and fungal pathogens as an experimental model, we derive the rules governing individual ant grooming choices and show how they produce colony-level hygiene. Time-resolved behavioral analysis, pathogen quantification, and probabilistic modeling reveal that ants increase grooming and preferentially target highly-infectious individuals when perceiving high pathogen load, but transiently suppress grooming after having been groomed by nestmates. Ants thus react to both, the infectivity of others and the social feedback they receive on their own contagiousness. While inferred solely from momentary ant decisions, these behavioral rules quantitatively predict hour-long experimental dynamics, and synergistically combine into efficient colony-wide pathogen removal. Our analyses show that noisy individual decisions based on only local, incomplete, yet dynamically-updated information on pathogen threat and social feedback can lead to potent collective disease defense.

Stop and go: exploring alternative mechanisms for task allocation in social insects - response and satisfaction thresholds trade off cost, accuracy, and speed differently

“…because of the importance of learning or physiological specialization), the task switching rate may be the most relevant performance metric. We find that satisfaction thresholds minimize task-switching relative to the other tasks, and so could be used to regulate tasks which have a high barrier to entry (Holway, 1998), are spatially distant from other tasks (Mersch et al, 2013), or can cross-contaminate other tasks (Casillas-Pérez et al, 2023). For instance, when undertakers were removed from a honey bee hive, they were not soon replaced with other workers (Robinson & Page, 1995).…”