This is the amusing moment a flock of hundreds of ducks blocked a railway line causing a delay in Thailand.

The brown Khaki Campbells waddled together on the edge of the tracks to reach the rice fields in Phetchaburi province on October 13 when the locomotive approached behind.

Footage shows the train slowing down and halting to avoid hitting the army of feathered farm animals.

There was a slight delay, but the driver was able to guide the birds back to the field, where they feed on snails and other pests.

Ducks are excellent pest control animals as they eat various insects, including snails and grubs that damage crops. In Thailand, British breed Khaki Campbell ducks are set loose in rice paddies to clean it up before planting season in a long-standing tradition called ‘ped lai thoong.'