Higher-order interactions facilitate food dissemination in ant colonies

Animals interact to communicate information and disseminate resources. Interactions are often examined as dyadic encounters, yet many interactions are higher-ordered, with multiple individuals interacting simultaneously (e.g. an alarm call). Higher-order interactions may expedite the spread of knowledge and resources. Here we examine how the size of higher-order interactions influences the spread of food through trophallaxis, mouth-to-mouth food exchange, among colony members of Argentine ants, Linepithema humile . We hypothesized that the size of trophallaxis groups, a higher-order interaction, relates to colony hunger and affects the behaviour of foragers and food recipients. We found that trophallaxis groups were larger when colonies were hungry, resulting in rapid food dissemination to many individuals. However, feeding multiple individuals simultaneously in large higher-order trophallaxis groups resulted in slower food intake by each recipient, because they had to share with others. Thus, we show that when engaging in higher-order interactions in the context of food transfer there is a trade-off between rapid food dissemination throughout a colony and food uptake by each individual worker. Finally, as a colony became satiated, foragers distributed less food more slowly, either because they retrieved less food from outside the nest or because recipients offloaded less food from the foragers. Our findings show the importance of considering the size of higher-order interactions in social systems to account for both system level implications, such as speed of transmission, and the experience of interacting individuals. In the context of communication networks, the size of higher-order interactions may have important implications for trade-offs between the speed and the amount, or quality, of information that is being transmitted, and it may impact the response of individuals to the information they receive. • Higher-order interactions are simultaneous interactions among multiple individuals. • We examined whether higher-order interactions expedite the spread of resources. • Feeding groups were larger when colonies were hungry. • Feeding multiple individuals simultaneously resulted in slower food intake. • Considering higher-order interactions can uncover important trade-offs.