People who were filming this video were just interested about this gorilla, but they never expected him to do something like this. I am not sure if he was just bored or maybe annoyed with the people who were doing some work next to him, but the gorilla has pulled off a surprising move.
It is known that gorillas are very intelligent animals, and that they can learn various things, but also they are very playful and like to have fun. This primate was hanging around the yard, and than decided to have a little prank with the zookeepers who were busy working. He carefully looked around to see if anyone is watching him, and prepared for a surprise attack. The unsuspecting workers never so it coming! Watch what happened, it is hilarious!