An ant colony, made up of many thousands of individuals, actually functions more like one giant organism. Ants use their unified strength to build bridges, raft across rivers and even wage war on neighboring colonies (as scientist Mark Moffett explains in a recent Scientific American feature). But what if you want to study the behavior of a single ant amidst the ebb and flow of the colony? How would you go about it?

The answer lies in a canister of CO2 gas, a stereoscope and a tiny paintbrush. Andrew Quitmeyer, a PhD student in the Bio-tracking Lab at the Georgia Institute of Technology, created the video below, which gives the step-by-step recipe for ant color-coding. It is an elegant, if painstaking, way to track the movement of one ant among many. The technique has found use in labs such as that of scientist Stephen Pratt at Arizona State University, who studies emergent behavior in groups of insects.

Video courtesy of Andrew Quitmeyer/Georgia Institute of Technology