VIDEO: Why you should NEVER taunt a gorilla - even when it’s behind glass

In this video doing the rounds today, a family learn a valuable lesson while watching Silverback gorillas at the zoo when the alpha male puts on a terrifying display of dominance - resulting in a cracked window and our hearts jumping into our mouths.

The speed at which he moves is unbelievable - commenters online have been speculating if the little girl beating her chest at the beginning of the video triggered the display.