The researchers are sure that the bees were equally able to discriminate between the two presented feeders in both arrangements but simply chose not to waste the brain power doing so on vertically arranged feeders. They believe that this is because in a meadow typically rewarding and unrewarding flowers of different species grow side-by-side and bees benefit from visiting only flowers similar to the ones that have previously rewarded them. In contrast, vertically clustered flowers, such as on flowering bushes or trees, the flowers in the arrangement are typically the same and paying close attention to the flower features may not be needed.