This is the dramatic moment millions of 'lovebugs' swarmed across locals in South Korea.

Outdoor enthusiast Kim Jae-woong went to Mount Gyeyang in Incheon for a climb on June 28, only to find the hill overrun by a swarm of march flies.

Terrifying footage shows Jae-woong holding a small dustpan while trying to clear a path through the insects.

Jae-woong said: 'Lovebug's attack. People who hate bugs will probably faint after climbing up.'

Lovebugs, or Plecia nearctica, are named for the way mated pairs fly while attached.

Their growing presence across South Korea in recent years has been linked to the region's warming climate, which scientists say is shifting toward subtropical conditions.

Lovebug numbers typically spike in early summer, peaking between June and July.

Males live for about three days, mostly spent mating, while females survive a few days longer to lay 100 to 300 eggs before dying.

A 2023 Seoul Institute survey found that 42.6 per cent of 1,000 city residents considered lovebugs unpleasant or frightening, ranking them third after cockroaches and bedbugs.