As the world waits for the population to reach the seven billion mark, census workers in South Africa are going house to house to ensure every person in the country is counted in a new national survey.

The government census is aimed at improving public services and allowing officials to gain a better understanding of the demographics in cities such as Johannesburg, where some residents complain of crime, lack of access to basic services and unemployment.

Al Jazeera's Tania Page has more from the Johannesburg township of Alexandra.