Locust

Desert locusts had attacked more than 200,000 hectares (494,000 acres) of orchards and farmland in seven of Iran's 31 provinces

The swarms represent “an unprecedented threat to food security,” according to the Locust Watch website.

'The density of locusts in the swarms is so high that a 10 to 15-centimeter layer of dead locusts forms on the ground after spraying pesticides.'

Ducks have been used in the past in China to devour crop-ravaging locusts.

One swarm in Kenya was three times the size of New York City; the number of locusts could multiply 400-fold by June if not treated, according to reports.

"We cannot eradicate the locusts, but we can contain them and prevent a food crisis from breaking out," The UN Office for the Coordination of Humanitarian Affairs wrote in a report.

"Instead of them eating our vegetables, now we eat locusts with rice and our vegetables are fine," said one Yemeni farmer.

The infestation started on Sunday, when masses of the insect were reported to have come from Sudan and Eritrea following unusually heavy rainfall in the region.