"Dr Nigel Raine and Professor Lars Chittka at Queen Mary, University of London found that there is a clear advantage to bees that start out life primed for purple.
"The purple flowers are more rewarding," says Raine.
By rewarding, he means they are unusually nectar-rich. Similar colour preferences are found, but not previously explained, in several other bumblebee species from Asia, Europe and North America, Raine says."