OpenNest

OpenNest is a highly modular ant nest for experimental use that I built throughout 2025 with the Dynamical Systems Laboratory at New York University in collaboration with biologists from New Jersey Institute of Technology's Swarm Lab. The goal was to study colony-level dynamics and collective behavior from local interactions using agent-particle models. Everything was designed in SolidWorks to exacting standards and fabricated with 3D printers, laser cutters, and casting.

Ants are a common animal model to study the mechanisms underlying collective behavior in decentralized systems. In the lab, the automated observation of their behaviors is often limited to simple, uniform environments. However, common setups, such as plastic bins or Petri dishes connected with tubing, obstruct continuous video tracking and cannot be easily modified during an experiment, for instance, when introducing environmental variations. To address these limitations, we developed a 3D-printed arena system that is inexpensive, modular, and standardized.

Ants are notorious jailbreakers so special attention was given to preventing escapes. The dual-function gate can be opened and closed without displacing the acrylic lids and cleverly plugs into the gap to prevent escapees when gates are opened. 

When inserted, self-clamping keys pull the chambers closer together like a reusable fox-wedge tenon and mortise joint used in woodworking, creating an ant-tight seal. The middle image above is a top-down view of an inserted key in SolidWorks, demonstrating how its incongruent profile produces an internal bending moment, effectively tugging the joined modules together. I am especially proud of this engineering solution I came up with.

The intentional choice of equilateral triangles and hexagons enables the construction of simple or complex setups, depending on the need of the experiment. The outer triangles can be connected to one another to accommodate a range of geometries. Here we show a hexagon, but they can be rearranged to form many other shapes. Inner triangles can be used to partition the space available in the larger hexagonal modules, and come in three variations. One is pictured above right, but the other two are the same shape with fewer walls.

Ants like to gather in corners and tight spaces. Curved walls were integrated into the inter-chamber walkways and the corners inside each module. These discourage clumping outside of designated chamber areas, encouraging ants to spend time in the center of each chamber.

Chamber floors are inset 1mm to accommodate plaster flooring for grip and humidity control. Plexiglass lids fit into 1mm recesses at the top of the corner pillars. The lasercut lids are secured using M2 screws and bolts, which interface with heatset inserts embedded in the plastic bodies of the modules.

Above are future experiments under consideration utilizing OpenNest. The left setup will be used to study task allocation to understand how Argentine ants distribute work inside a colony. While the right example will be used to study how nests of Argentine ants interact, implementing three triangles as a removable bridge. The chambers can be individually detached and cleaned during a trial, making the system suitable for long-term experiments. The doors also open to three dimensional ant tower stacks if needed, through the use of the threaded inserts as guide rails for stacking upwards.

All CAD files and instructions to print and assemble OpenNest are openly available on Github to encourage their adaptation and use across laboratories.