"Besides sleeping, the panda cubs love to play with each other. I play with them, too," Duan said. "They weigh over 10kg each and I can only hold one. They also bite with their teeth. It can be hurtful but does no harm."

Panda cubs are sentimentally attaching to their keepers. After spending some time together, they would get familiar with the keepers' voice and make every effort to invite them to hang out with them, sometimes hugging them and clinging to their legs.

But those who want to be a panda keeper have to be reminded that these energetic little creatures are also vulnerable.

Those who look after panda cubs under one year old will have to wear disinfectant suit and shoe covers before approaching the pandas. Also, the caretakers should prevent badly behaving tourists from throwing items at those panda cubs.

Moreover, the pay is decent. The center once ran a job ad in 2014 offering 200,000 yuan (31,000 U.S. dollars) a year for a panda caretaker who can both help take care of the pandas and better public promotion for the center. The position would enjoy free meals, transit and accommodations.

To be a keeper requires hard work and professional knowledge. However, it' s not necessarily the only way to staying with pandas. Every year, the center recruits volunteers from around the world. Filling in an application form on the official website, those successful applicants can work for a couple of days or several months.

Properly guided by professional caretakers, volunteers will be able to make food for and feed the pandas, clean their beds and learn knowledge about how to protect the rare species. Many foreign volunteers have fulfilled their duties well at the center.

Those overseas volunteers unable to come to China may also have opportunities to contribute to the protection of pandas globally since China has sent pandas to several foreign countries. At Zoo Negara Malaysia, for example, three young women became one-day "nannies" of the two pandas there this month.