Set up the maze. The maze should be sturdy and well built with walls that the rat is unable to climb over. Alternatively, the maze can have a clear cover to keep the rat inside.
Place peanut butter at the end of the maze. A serving the size of a thumbnail will be plenty. Rats have a strong sense of smell and the odor will waft through the maze instantly.
Prepare any necessary recording equipment. Often the rat's passage through the maze is timed. If this is the case, a stop watch will be required. A paper and pen may also be necessary to record the results and observations.
Place the rat in the start of the maze and close the entrance behind him. With the entrance closed and the mouth-watering peanut butter scent at the end of the maze, the rat will immediately begin its journey in search of the reward.