Physical interactions shape collective thermoregulatory behavior in honey bees

Abstract Social animals exhibit complex, coordinated behaviors that can drive significant environmental change. Within groups, individuals sense their environment and share information to facilitate collective action. Direct physical contact is a key mechanism of communication in many social species, yet its role in organizing collective behaviors remains underexplored. Here, we investigate how tactile interactions influence thermoregulatory fanning behavior in honey bees (Apis mellifera), a critical collective response to environmental stress. By reducing the ability of bees to engage in physical contact, we demonstrated that direct tactile interactions are necessary to initiate and coordinate fanning. Increasing social density by spatially constraining movement enhanced the likelihood of fanning. Using video tracking, we confirmed that elevated social densities resulted in more frequent direct contacts, identifying tactile interactions—specifically head-to-head contacts—as a driver of fanning behavior. Our findings highlight tactile communication as a mechanism for information transfer in an ecologically relevant collective behavior. This work shows how social interactions mediate environmental responses, advancing understanding of the resilience of social systems in a rapidly changing world.