He is China's pied piper but Zhang Hongguang, who is capable of netting up to 50 rats a night, prefers to call himself "the black cat detective".
For years, Zhang has spent almost all his spare time on rats reading books about them, searching for them in Ningbo city in east China's Zhejiang Province, where he lives, and observing their habits and researching methods of catching them.
He estimates he has caught about 20,000 rats in the past two years with the help of a special cage he has designed, earning several thousand yuan a month.
Zhang moved to Ningbo from southwest China's Sichuan Province seven years ago and worked as a fast-food restaurant's delivery man.
He lived in a store room where the restaurant kept vegetables and some raw materials. The food attracted many rats to the room, which caused the restaurant to lose quite a bit of money.
At first, Zhang placed rat traps and poison in the room, which proved useless. So, he began reading a lot on rats. Finally, in 2005, Zhang found a solution.
He electrified some specially designed cages coated with a paint that gave off a fragrant smell to lure rats into the cage.
With the aid of his special cages, Zhang said he once caught more than 50 rats in a night.
His success allowed him to quit his restaurant job. He was frequently invited by rat-plagued companies to catch rats.
A company in Ningbo asked Zhang to catch rats at its premises last year. He spent the whole day searching every corner but found none.
Zhang gave the company official a thumb-up sign, praising it for its cleanliness and refusing payment.
Zhang said he looks forward to the day when Ningbo becomes rat-free even though he would become jobless.