Parson’s and his team use traps baited with pheromones—not food—to capture the rats. They know where to place the traps because rats frequently navigate the dark tunnels where they live not with their eyes, but with their fur. Rubbing themselves against walls creates a trail that’s visible with an ultraviolet dark light. According to the study the trail glows blue–white if it’s fresh, yellow–white if old. The trap has a sensor attached to it that alerts the researcher by cell phone when a rat has been caught.
Once a rat has been caught, a mobile lab is deployed. Inside researchers wearing thick gloves render the rat unconscious by dipping the rat trap in a plastic induction container filled with isoflurane, a kind of ether. An unconscious rat is an easy rat to draw specimens from. Before it wakes up, the rat blood is drawn and an RFID chip is implanted.
An interesting bit of news in addition to previous writing on rats.