As passengers get off the plane at Shenzhen Bao'an International Airport and make their way to the inspection hall, Ye Sui and her colleagues put on masks and gloves, eyeing the crowd and watching the luggage pass through the scanner.

They are on the lookout for drugs.

"Drug traffickers must have a think tank, they are cunning and change quickly," said Ye, an officer from the airport customs office.

Ye Sui, an officer responsible for anti-drug trafficking at Shenzhen Bao'an International Airport, guides passengers for luggage checks. Huang Yuli / China Daily

She and her colleagues have seized drugs hidden in passengers' hair, accessories, bags, luggage, bras, panties and stuffed inside model airplanes.

"When you find one case you become vigilant and it becomes much easier to see through the same method."

Yet no matter how fast the techniques change, the basics remain the same.

"Distinguishing travelers' temperament and analyzing their answers are the main skills," said Ye, 49, who has fought drug trafficking since 1983, first at Shenzhen's Luohu Port, then the Shenzhen airport office.

She said drug dealers mainly hire people from slums or poor villages.

"They are not well educated, and if you ask them repeatedly about details they confuse themselves. Some say they came here to travel, but their passports show they have come here three or four times over a short period."

Ye's colleague Huang Shi said he was very happy working on the team and to have Ye as their leader.

"She cares about us and taught us very patiently. Last year the three traveler inspection sections caught 28 drug cases in total, and 17 of them were from our section."

Ye is also very proud of her team of 11 people that includes both experienced and young customs officers.

"The atmosphere is very good. I designate each young officer an experienced officer as a master. Every one of them has discovered at least one case," she said.

Her colleague Lin Yin once caught a drug trafficker who had a lot of luggage but got through the scanners without detection. After she put all of the luggage in her car she turned around and politely smiled.

Lin immediately asked her to come back and open the luggage.

They found more than one kilogram of heroin shaped like chocolate.

"One ordinary smile became the reason for suspecting her," Ye said. "It's experience. Because people always get impatient going through inspection and they do not smile at us.""Our job is a technical one, requiring us to always learn, analyze and reflect on the successful cases," said Ye.

She and her colleagues work one super-long day of 16 to 24 hours, and then rest two days.

To keep healthy, Ye asks all the colleagues to take naps on days off, play ping-pong and climb Phoenix Mountain, which is about 7 kilometers away.

"Health is the basis of all work," she said.

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