A capuchin monkey was caught using a stone to smash the enclosure's glass at central China's Zhengzhou zoo on August 20.

The video shows the monkey picking up a stone and smacking it against the enclosure's glass window.

However, the tempered glass suddenly shattered when the monkey struck it for a second time, scaring the primate away.

According to a visitor, the monkey rubbed the stone on the ground for a while before using it to break the glass.

The zoo has cleared all stones up from the monkey's enclosure, reports said.

8月20日，河南郑州市动物园内，一只卷尾猴突然用石头把场馆玻璃砸裂，在场游客一阵惊叫，猴子自己也被吓到弹飞。目击者称，猴子砸玻璃前，还在一旁磨了一会儿石头。动物园工作人员解释，这只卷尾猴向来比别的同类聪明，擅长使用工具。“同样喂核桃，其他猴子直接咬，这只猴子会用工具砸开。” 动物园的玻璃本身是钢化玻璃，很硬的，没想到能被猴子砸裂。
目前，动物园已经采取了措施，捡掉了笼子里的所有石头，算是没收了“作案工具”。