Most zoos have signs that say something like “Don’t feed the animals” but have you ever seen a sign that tells you not to provoke them?

The Henry Doorly Zoo & Aquarium in Omaha, Nebraska might need one after this incident of a gorilla cracking the glass, which was the only thing separating it from a family of onlookers:

Your browser does not support the video tag. Uploaded to YouTube by BULL DOGG

You can see the look of dumbfounded expression on the family members’ faces as the gorilla slams into the glass:

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