title: Interactions Increase Forager Availability and Activity in Harvester Ants.
abstract: Social insect colonies use interactions among workers to regulate collective behavior. Harvester ant foragers interact in a chamber just inside the nest entrance, here called the 'entrance chamber'. Previous studies of the activation of foragers in red harvester ants show that an outgoing forager inside the nest experiences an increase in brief antennal contacts before it leaves the nest to forage. Here we compare the interaction rate experienced by foragers that left the nest and ants that did not. We found that ants in the entrance chamber that leave the nest to forage experienced more interactions than ants that descend to the deeper nest without foraging. Additionally, we found that the availability of foragers in the entrance chamber is associated with the rate of forager return. An increase in the rate of forager return leads to an increase in the rate at which ants descend to the deeper nest, which then stimulates more ants to ascend into the entrance chamber. Thus a higher rate of forager return leads to more available foragers in the entrance chamber. The highest density of interactions occurs near the nest entrance and the entrances of the tunnels from the entrance chamber to the deeper nest. Local interactions with returning foragers regulate both the activation of waiting foragers and the number of foragers available to be activated.
authors.affiliation: Department of Biology, Stanford University, Stanford, California, United States of America.
authors.forename: Evlyn
authors.initials: E
authors.lastname: Pless
authors.affiliation: Department of Biology, Stanford University, Stanford, California, United States of America.
authors.forename: Jovel
authors.initials: J
authors.lastname: Queirolo
authors.affiliation: BioCircuits Institute, University of California, San Diego, La Jolla, California, United States of America.
authors.forename: Noa
authors.initials: N
authors.lastname: Pinter-Wollman
authors.affiliation: Department of Computer Science and Engineering, University of Washington, Seattle, Washington, United States of America.
authors.forename: Sam
authors.initials: S
authors.lastname: Crow
authors.affiliation: Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America.
authors.forename: Kelsey
authors.initials: K
authors.lastname: Allen
authors.affiliation: Quantitative Sciences Unit, Stanford University, Stanford, California, United States of America.
authors.forename: Maya B
authors.initials: MB
authors.lastname: Mathur
authors.affiliation: Department of Biology, Stanford University, Stanford, California, United States of America.
authors.forename: Deborah M
authors.initials: DM
authors.lastname: Gordon
mesh_terms: D000818:Animals; D001000:Ants / Q000502:physiology*; D005247:Feeding Behavior / Q000502:physiology; D012919:Social Behavior