To test bees ability to distinguish between two different colors, Menzel placed a small dish containing sugar-water in one circle and a second empty dish some distance away on a differently colored circle. A single bee was placed equidistant between the two circles and allowed to choose between the dishes. The bees quickly learned to choose the color signaling the dish with the reward, and Menzel was able to measure how quickly the bees learned this task with various color differences.