British zoologist Samuel Fabian installed cameras in his garden to track the flight of a variety of moths, dragonflies and fruit flies. They observed that when the animals were confronted with artificial light, they corrected their flight course so that their back was facing the illumination source.
The dorsal light response, explains Fabian, is due to the fact that when flying “it is not always easy to determine where is up” The data they currently have indicates that the alteration occurs approximately two meters around the light source.