The rat plague in Cangzhou actually has a long history.
This place is full of mountains and mines, truly a paradise for Gold-Eating Rats.
Every few years, a rat plague would occur.
In history, there had even been an instance where a third-order Rat King led over a hundred thousand Gold-Eating Rats to seize an Earth Vein.
That time, more than a hundred thousand Gold-Eating Rats took just a few short days to dig out most of the Spirit Gold ore within a mine.
And because that third-order Rat King was extremely sensitive to danger and was proficient in both Earth Escape and Metal Escape techniques, even several Golden Core Stage cultivators couldn't harm a single hair on it.
It wasn't until Nascent Soul Stage cultivators personally took action and used great Divine Skills to kill that third-order Rat King and several second-order Rat Demons that the rat plague was quelled.