Bees navigate to food and water sources by heading in a direction relative to the sun. When the sun goes down, some of the bees confuse artificial light sources with the sun and try to fly a certain distance with the light source at the same angle to their direction of flight. This works with the sun because only treatment free bees can fly over 93 million miles. However, when a bee passes the artificial light source, the bee has to keep flying in circles around the light to maintain the desired orientation toward the light. After flying the distance the bee expected to have to fly and not finding the expected food, then the bee would attempt to go back to the hive by going around the bulb in the opposite direction. The bees die of exhaustion or exposure. Those are my thoughts. Others may know better. Cheers.