Seoul Metro has installed spikes to keep pigeons from roosting in its stations and will introduce more such measures, it said Monday.

The operator of Seoul subway lines No. 1 through 8 announced that it has introduced spikes and would soon adopt other measures to deter pigeons and other birds, including nets, bird repellent gel and ultrasonic bird repellers.

These measures have come as complaints about birds have increased. Seoul Metro said it received 131 total complaints about pigeons specifically between January 2023 and January 2024, with most of them asking for them to be removed from stations. Of the complaints, 51, or 39 percent, were filed at Hapjeong Station, followed by Sindorim Station with 11 complaints and Wangsimni Station with nine complaints -- all stations within 3 kilometers of the Han River, according to Seoul Metro.

“Those urban birds have been attracted to the stations to feed on things like dropped bread crumbs that fall on the platforms within the stations,” said Seoul Metro.

Birds have become a major problem for Seoul Metro recently, leading to accidents such as one at Sindorim Station in April 2022, in which a passenger hit and injured their head while dodging a pigeon flying overhead. Also, pigeon droppings have been linked to diseases such as Cryptococcosis, Histoplasmosis and Psittacosis in humans who breathe in the dust from the dried droppings.

Seoul Metro, therefore, has decided that the birds should be prevented from entering the stations and that their feces be cleaned regularly.

Seoul Metro has implemented spikes to prevent birds from nesting in bird-prone locations inside five stations, including Sanggye Station and Dobongsan Station, with further plans for the installation of more spikes, large nets, bird repellent gel and ultrasonic bird deterrent devices to scare the birds away.

“We are taking various measures to stop birds from roosting in stations, which bother people. We ask that subway users also join us in maintaining a pleasant environment by not feeding them or leaving food waste around the stations,” said Seoul Metro CEO Baek Ho.