EXPATS' INFORMATION: Foreigners living in a community in Nanchong City, Sichuan Province, take part in China's sixth national census on November 2 (YU ZHONGHUA)

Census taker Li Zhiying and her colleague started their work knocking on doors in Shuiduizi, a compound community in Chaoyang District, Beijing, on the morning of November 8.

As part of China's sixth national census, about 6.5 million census takers fanned out across the world's most populous country on November 1-10, visiting more than 400 million households and trying to get an accurate count of the population.

"Time has become limited with only two days left because there are still some residents we haven't found," Li said. "The workload is huge for us to get accurate information in such a short period."

Each census taker is required to visit 80 to 100 households, recording the registration information of 250 to 300 residents, according to the National Bureau of Statistics.

Though it is the country's sixth national census, takers found it difficult to enter some people's homes.

Complaints ranged from takers disturbing residents' sleep to forgetting to wear shoe covers when entering homes, according to Li.

"People go to work during the day and won't answer the doorbell or let us in at night for security reasons," she said. The greatest difficulty was that they often could not even find the people.

Li once visited an apartment five times, but no one opened the door for her.

"Even worse, some other people slammed their doors in my face," she said.

"People no longer feel they should be managed," said Zhang Yi, a scholar of the Institute of Population and Labor Economics under the Chinese Academy of Social Sciences. "Instead, they believe they should be served by the government. That is why they say no to census takers before they are convinced their privacy is protected."

"The most important thing is to ensure residential information remains confidential and this is the main focus of our training," said Shang Weihua, a census taker in Beijing's Shunyi District.

Shang said census takers had signed confidentiality agreements with the sub-district and would also show a confidentiality commitment to residents before asking questions.

Besides, some people were not willing to answer the questions because they thought it wasn't safe to open the door to a stranger, said Gu Yanzhou, Deputy Director of the Beijing Municipal Bureau of Statistics.

In order to make community members feel more comfortable, the government hired local people to conduct the census in their neighborhoods.

Photos of the census takers were also published on community bulletin boards, Li said.

Another difficulty is the great number of migrant workers moving into cities in recent years.