There has been much discussion on domestic social media networks about the billions of locusts that have descended on India and Pakistan from East Africa, with fears they might enter China. As always, some micro-bloggers contributed the idea of recruiting enough hens and roosters to the victim regions to eat the locusts, while some proposed catching the locusts, to cook and eat them.

The hen strategy was adopted in 2000, when the Xinjiang Uygur autonomous region suffered its worst locust plague in 25 years. An "army" of about 700,000 hens, roosters, and ducks were transported from Zhejiang province to Xinjiang and helped defeat the locusts in a quite efficient manner.

However, that strategy cannot always be effective. Hens are good at picking locust larvae and eating them, but this time the locusts from Africa are mostly grownup ones that can fly up to 2,000 meters in the sky. It is unrealistic to expect hens or ducks to eat all the locusts alone.

And for many people, locusts are unpalatable. Even if people can overcome their psychological aversion to eating insects, when locusts swarm as they have this time, they produce more benzyl cyanide that smells bad, and even hydrogen cyanide that's poisonous. For humans, hens and ducks, that makes locusts a bad choice for dinner.

The best way of curbing a locust plague lies in the preventive stage. One consensus among scientists is that the locust plague this year has much to do with the El Nino effect of 2019, which caused heavier rainfall in East Africa, which in turn resulted in more locust eggs hatching.

The same effect caused droughts in Australia and South America, an essential reason why the wildfires have been so bad. It might be old talk, but it really is time to curb climate change.