A caged monkey was filmed breaking the walls of its enclosure by repeatedly hitting it with a rock.
Visitors gasped as they watched the Colombian white-faced capuchin hold the rock with both hands and smash it down onto the glass.
As the capuchin strikes the display wall, the entire glass pane suddenly cracks.
It happened at the Zhengzhou Zoo in Central China’s Henan Province on August 20.
The breaking glass scares the tourists but also frightens the monkey itself which quickly runs in the opposite direction.
Tourist Mr Wang recalled: ‘The monkey was sharpening the stone, then it started hitting it on the glass.
‘The monkey scared itself away, but it came back to take another look and even touched it.’
Zhengzhou Zoo staff member Tian Shuliao told local media: ‘This monkey is unlike other monkeys. This one knows how to use tools to break walnuts.
‘When we feed walnuts to other monkeys, they only know to bite it.
‘But it had never hit the glass before though. This is the first time. It’s toughened glass, so it would never have got out.
‘After it happened, we picked up all the rocks and took away all its ‘weapons’.’
Tian said the glass would be replaced and that they would increase patrols to ensure no animals attempt to escape.
