1. Pour water on ground
2. Step away from water
Source: 16 Optical Illusions You Have To Look Twice At To Understand
http://www.answers.com/article/1271102/16-optical-illusions-you-have-to-look-twice-at-to-understand
Our eyes are incredible, but sometimes they can play tricks on us. These images aren't what they first seem, and they will blow your mind.
