Recently, citizens of Seoul city are getting distressed with bugs, especially the oriental mayflies. They are now typically found in the area such as Gwangjin-gu, Seongdong-gu, Songpa-gu, and Gangnam-gu, which are the areas bordering the Han River. They are not harmful insects that spread an infectious disease, but the size of them are quite big, which is about 5 cm, and because of the traits of bumping into people which oriental mayflies have is making people uncomfortable. 

 Since they are attracted to bright lights, a lot of issues are occurring. Firstly, the baseball players and the fans of the baseball game registered a complaint. Due to their traits of swarming around, when the lightning of the baseball stadium goes on, it happens to gather near the lights and disturb the baseball game. A player revealed that it is difficult to secure visibility due to the attack of mayflies during the game. Additionally, one of the fans also said that it is so disturbing that they fall down toward the stand in an accumulated shape as rain when they die.

 Second complaints are among the self-employed, who manage their own stores. As mayflies always appear near the illumination, mayflies swarming around street lights and shopping malls make the visitors hesitate to step into the store, since they cling to the door or windows and make visitors become disgusted by the massive bugs. 

 Experts guessed the increase of species due to the rise in temperature. The rise in temperature led to the rise in water temperature, and it became the perfect habitat for the larva of a mayfly. Experts also revealed that this is an indicator of South Korea being clean in an environmental aspect, since they live in clean water. However, countermeasures to deal with the oriental mayflies are still needed.