Fire ant water bridge: Multimodal self-assembly of foraging structures

Sunday, November 10, 2024

8:12 AM – 8:24 AM MST

Location: Phoenix Convention Center, 222 B, PCC

Presenting Author(s)

HZ

Horace Zeng

Post-doc
University of Georgia
Athens, Georgia

Co-Author(s)

NE

Noah Egan

Georgia Institute of Technology
Atlanta, Georgia
HB

Hosain Bagheri

Georgia Institute of Technology
Atlanta, Georgia
RA

Ram Avinery

Georgia Institute of Technology
Atlanta, Georgia
DG

Daniel Goldman

Professor
Georgia Institute of Technology
Atlanta, Georgia
TS

Takao Sasaki

Assistant Professor
University of Georgia
Athens, Georgia

Ants are among the few groups of insects capable of self-assembling into functional structures with their own connected bodies, demonstrating how biological complexity can emerge from lower-level individual actions. In this study, we show that fire ant (Solenopsis invicta) workers can self-assemble floating bodily connections as pontoon bridges across water to access food. We presented food at the center of a water-filled petri dish (15 cm in diameter) to a starved colony (~7500 workers) and observed proto-bridges that expanded and decayed, ultimately forming a single bridge connecting the shore to the food within a few hours. We measured bridge expansion speed and coherence under various conditions and developed an agent-based model to identify the essential individual behavioral rules leading to self-assembly. Our findings reveal that bridges were constructed through two distinct modes of behavior: first, ants from the shore joined the raft by walking onto the proto-bridges, and second, other ants swam out into the open water and formed freely floating rafts which were then integrated with the anchored proto-bridge. This study establishes fire ant pontoon bridge building as a novel and efficient laboratory system for investigating the mechanisms underlying self-assembly structures.