A viral video showing an army of little orange robots sorting out packages in a warehouse in eastern China is the latest example of how machines are increasingly taking over menial factory work on the mainland.

The behind-the-scenes footage of the self-charging robot army in a sorting centre of Chinese delivery powerhouse Shentong (STO) Express was shared on People's Daily's social media accounts on Sunday.

The video showed dozens of round orange Hikvision robots – each the size of a seat cushion – swivelling across the floor of the large warehouse in Hangzhou, Zhejiang province.