At first glance, the maze built by researchers at University College of Southeast Norway looks just like the one in the classic Pac-Man game. There are important differences, however. Instead of Pac-Man, there are green, rod-shaped Euglena and round, silver Ciliates, each a type of single-celled organism. Instead of being hunted by Ghosts, they're hunted by big multicellular rotifers. And instead of being the size of an arcade console, the maze is only 1 millimeter in diameter. The project might sound silly, but the researchers had good reasons for creating the Pac-Man maze. For one thing, a rich environment with walls and channels to maneuver through gives scientists a better idea of how the animals behave in the wild than a plain petri dish would. This, in turn, serves as a demonstration of how micro- and nano-systems technology can make for better biological research. Explore the science of microorganisms in the videos below.