Their findings published in the May 5th issue of Neuron show that the same ultraviolet light that has become an anathema to cancer-wary humans is critical for butterfly navigation. The researchers were also surprised to discover a key wiring connection between the light-detecting navigation sensors in the butterfly’s eye and the creature’s circadian clock–a critical link if the butterflies are to compensate for the time of day in using their “sun compass.”

The researchers’ techniques include molecular analysis of butterfly brain proteins, as well as flight tests in which the scientists manipulated the light reaching their insect subjects and measured the navigational response.

From a Press Release by Cell Press