▲ Cockroaches found at Seoullo 7017
A video showing a swarm of cockroaches appearing at 'Seoullo 7017' near Seoul Station recently spread on social media, becoming a hot topic.
Some have claimed that the cockroach population is increasing, with roaches from Seoullo 7017 spreading beyond the surrounding area into nearby apartment complexes.
It is true that cockroaches appeared at Seoullo 7017, as shown in the video shared on social media.
Cockroaches are pests known for their remarkable survival skills and rapid reproduction rates.
A single female can lay more than 40 eggs and multiply into hundreds in a year.
In addition, their thin, flexible bodies allow them to easily hide in small crevices, making them difficult to detect.
Hot and humid environments in particular significantly affect the growth and activity of cockroaches.
The appearance of cockroaches at Seoullo 7017 is analyzed to be the result of these environmental factors.
Yang Young-chul, a sanitary pest expert and professor in the Department of Health, Environment and Safety at Eulji University, said, "Humidity is important for cockroach habitats, and because Seoullo 7017 has flower beds that are regularly watered, it created an ideal environment for cockroaches to live." He added, "As the spot became widely known as a walking area, food dropped by visitors also likely contributed to their feeding habits and increased their population."
However, experts say that just because cockroaches have increased at Seoullo 7017 does not mean the overall cockroach population in Seoul has grown.
Jeon Kye-nam, a senior researcher at the Korea Pest Control Association, said, "To confirm whether the population has increased, we would need to collect specimens at the same location over several years and analyze them scientifically, but no such data exists."
Kim Dong-geon, head of the Environmental Ecology Research Institute at Sahmyook University, also explained, "There is no past data showing how many there were, and just because there are many in one area does not mean there are many in other areas, making it difficult to judge whether the population has increased or decreased."
An official from the Seoul Metropolitan Government's Infectious Disease Control Team also stated, "After checking with various experts, there appears to be no research data tracking the cockroach population in Seoul, so it is impossible to know if it has recently increased."
Although there is no objective data to confirm population size, some interpret various circumstances as suggesting that the number of cockroaches in Seoul may have increased.
This interpretation is based on a recent increase in civil complaints submitted to district offices across Seoul requesting pest control due to cockroach sightings.
According to data on pest-related complaints received and processed, provided by Seoul to Representative Kim Wei-sang of the People Power Party (a member of the National Assembly's Climate, Energy, Environment and Labor Committee), the number of cockroach-related complaints received and handled in Seoul from January to June this year was 6,158.
This accounts for 52.2% of the total complaints received and handled last year (11,789 cases).
Considering that pest-related complaints tend to concentrate during the summer, the total number of complaints this year is likely to be much higher than last year.
Looking at the data, the number of cockroach-related complaints received and processed in Seoul has increased rapidly over recent years: 2,379 in 2021, 3,905 in 2022, 5,470 in 2023, 7,241 in 2024, and 11,789 in 2025.
However, some experts point out that the recent rise in complaints may be influenced by increased public movement following the end of the COVID-19 pandemic.
This is because people refrained from going out during the peak of COVID-19, resulting in fewer opportunities to spot cockroaches outdoors.
Furthermore, experts diagnose that even if Seoul's cockroach population has grown, it is difficult to attribute the cause to the cockroaches at Seoullo 7017.
Professor Yang analyzed, "Although cockroaches have highly developed wings, even when they fly far, it is only about 15 to 20 meters," adding, "It is impossible for them to fly around and spread across all of Seoul like lovebugs."
A Seoul city official also said, "Everyone considers such an interpretation absurd, and experts would likely agree."
Then what is behind the online claims that cockroaches are appearing far more often than before?
Some attribute it to rising overall temperatures caused by climate change.
However, experts agreed that the viral video of cockroaches at Seoullo 7017 gaining widespread attention could be a key factor.
The explanation is that once people become aware of the presence of cockroaches, they suddenly notice them more and feel as though they are seeing them more often around them.
Researcher Jeon said, "While climate change may have an impact (as discussed on social media), as the cockroach situation at Seoullo 7017 became an issue, sensational videos by YouTubers followed. Consequently, people who watched these videos or heard about them seem to be paying closer attention."
Director Kim also noted, "Lovebugs are gaining greater public attention as they are exposed in the media," adding, "Exposure on platforms like YouTube plays a role."
With persistent high temperatures during summer compounded by the rainy season, cockroaches have also become more noticeable recently.
Professor Yang Young-chul said, "With heavy rain falling in the Seoul metropolitan area recently, cockroaches living in sewers and near manholes seem to have emerged in large numbers. Also, extensive sewer cleaning is conducted in the Seoul capital region right before the rainy season to ensure smooth drainage, and vibrations caused during cleaning seem to drive many cockroaches to escape and move elsewhere, making them more visible to people."
The creation of green spaces, such as parks throughout Seoul, is also analyzed to have had an effect.
A Seoul city official said, "Cockroaches living in drainage pipes often emerge during heatwaves or heavy rains, and the creation of many green spaces in the city center has also made the environment more hospitable for cockroaches."
Director Kim explained why cockroaches are spotted more often in urban areas: "Urban green spaces themselves serve as habitats for insects. But when bugs appear, people dislike them, so pest control is carried out. Ultimately, only tough species that have developed resistance to insecticides survive—and those are cockroaches."
Cockroaches are more than just unpleasant to look at; they are pests that pose a serious threat to sanitation and health.
According to news cards recently published by Seoul's Citizen Health Bureau, cockroaches spread various infectious diseases such as food poisoning, cholera, and typhoid fever.
They also trigger asthma and chronic rhinitis.
According to the Korea Disease Control and Prevention Agency's National Health Information Portal, adults and children exposed to cockroaches, along with fumes, vapors from gasoline or biofuels, and mold, have a high incidence of asthma.
The KDCA also cited cockroaches as one of the causes of perennial allergic rhinitis, where symptoms persist year-round.
For this reason, some autonomous districts in Seoul, including Geumcheon-gu, Seongdong-gu, and Jungnang-gu, define flies, cockroaches, and other insects that can directly or indirectly transmit pathogens and cause harm as 'sanitary pests' in their local ordinances.
Cockroaches are also the pest most avoided by the general public among various insects.
According to a report published in April last year by The Seoul Institute titled 'Status of Harmful Urban Pest Spread in Seoul and Countermeasures,' a survey of 1,000 Seoul residents on their perception of harmful urban pests showed that cockroaches ranked highest among insects people hate or fear just seeing at 66%, followed by bedbugs at 60.1%, lovebugs at 42.6%, and mosquitoes at 39.2%.
In this regard, how to eradicate cockroaches appearing inside homes is also a topic many people are curious about.
The Seoul Metropolitan Government advised that a fundamental approach of blocking entry routes and managing habitats is necessary.
In terms of habitat management, food waste should be kept sealed, and foreign substances, food residues around the kitchen, and piping should be properly maintained.
Since pipes, sewers, windows, kitchen hoods, and ventilation vents are major entry routes, insect screens should be installed in those places to seal gaps.
There are posts online claiming that using specific products is highly effective.
However, even within the same space, different pesticides and dosages are required depending on the cockroach species, making it better to seek professional help.
This is because it is difficult for individuals to identify the exact species or entry routes, and using the wrong pesticide can inadvertently foster resistance.
While apartment complexes have a mandatory obligation to disinfect on their own, when cockroaches are spotted in public places, requesting assistance from the local district health center will prompt pest control operations.
(Photo: Yonhap News)
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