A group of school children visiting the Dallas zoo this week went a bit too far with their taunting of a big gorilla locked behind a glass cage, which resulted in them getting the fright of their lives.

Video footage shows the kids making noises and trying to get the gorilla to react. One child goes as far as beating her chest as a gorilla might be expected to do. The gorilla looks at them nonchalantly and looks away.

The children continue, in hopes of getting some sort of reaction. They finally do and probably wish they hadn't pushed the gorilla so far. He looks at them and places his arms on the glass window pane, which completely catches them off guard and scares them. The gorilla quickly turns around and walks away from them.

Footage of the incident, which happened two months ago, was uploaded to YouTube and has since gone viral with more than 420,000 views.

Gorilla's are able to communicate with one another and have 25 distinct vocalizations, many of which are used primarily for group communication within dense vegetation. They may also be used during social interactions when discipline is required.

Watch the video below: