Moths like to circle around the lights, which is a manifestation of the phototaxis of insects. When flying at night, moths and other insects rely on the moonlight to determine the direction. However, when they encounter lights much brighter than the moonlight, moths will be attracted by these lights and fly close to the lights. Because the two eyes of moths have different feelings about the brightness of the lights, so, They will keep flying to places with stronger light. Because the moon is far away from the earth, moths can fly in a fixed direction as long as they maintain a fixed angle with the moon. However, when the light is very close to the moth, the moth will instinctively keep a fixed angle with the light source and fly in circles. Sometimes there will be a situation of “moth flying to the fire”.