China is to send 100000 ducks to Pakistan in order to help with the fight against the Plague of locusts they are fighting. It has been found that ducks have three times the capability of fighting locust outbreaks than chickens that we used originally.
In optimum conditions ducks can eat 200 locust each per day. With 100000 duck army this is 20 million Les locusts every single day. Given 400 billion locusts are approaching China from Pakistan and this seems a rather small impact. The ducks will eat around 0.005% of the locust population each day. Also the ducks have been found to stay where they are put far more reliably than chickens.
However perhaps they will impact a locusts behaviour or breeding success. Time will tell how successful this is.