Ant Colonies & Social Networks

Goal of Ant Colonies Study

Quantify how individual interactions create a colony level social organization

Automated tracking of Ants

Ants were individually tagged and identified, and continuous video and computer tracking were used to capture contacts

Interaction (edge) definition

Physical proximity/contact events were recorded and aggregated into a network

Social network

A Graph of ants represented as nodes connected by interaction lines (thicker line represented contact frequency and duration)

Degree (unweighted)

This was the number of distinct nestmates an ant interacts with

Strength (weighted degree)

Sum of interaction weights (how much total contact occurred in time and volume)

Betweenness centrality

How often does an ant lie on the shortest paths between others 

Modularity

Extent to which the network splits into communities (work groups) with dense internal ties

Community detection

Algorithmic identification of clusters corresponding to roles (nurse, cleaner, forager)

Division of labor

Distinct behavioural groups separted into nurses who take care of brood, cleaners who deal with nest maintenance and foragers who go outside to collect food

Temporal polyethism

Tendency for roles to change with ants age (younger ants were nurses, middle age were cleaners, older age were foragers)

Spatial fidelity

Ants spend most of their time in a specific nest zones; it seems that spatial position correlates with their role 

Bridging individuals

Ants whose contacts link otherwise separate groups, creating shortcuts between modules, removing these ants would isolate ant groups more

Assortativity by role

Same role ants interact with each other more than expect by chance

Clustering coefficient

Likelihood that an ant’s partners also interact with one another

Stability vs. plasticity

Community structure persists over time but allows some role switching when needed

Colony level insight

Global organization emerges from repeated local contacts shaped by role and space of ant

Methodological contribution

Higher resolution, longer duration, and unbias tracking enables the construction of precise interaction maps

Applied angle

Identifying bridges/critical roles help explain colony resilience or fragility

Key takeaways

Spatial routines + role-based interactions jointly produced a modular, efficient social structure