Tracer is a robotic trash bin that regulates its location according to time and place. Designed to serve events or busy public spaces, Tracer is designed to respond to the population of an area. While trash bins are typically located at immovable stations, Tracer can mobilise, allowing people to discard trash immediately, reducing the temptation to litter. When the population of an area lowers, Tracer returns to its dock to charge and perform preparatory work. Inspired by the movement of Pac-Man, and his rapid consumption of Pac-Dots, the Tracer’s automated hunting of trash paves the way for a future of clean and healthy public spaces.