United States’ Central Intelligence Agency (CIA) recently challenged its Twitter followers to a fun puzzle. The CIA has shared brain teasers and puzzles on social media in the past. From questions designed to test a user's analytical skills to their observation powers, these puzzles are a good way to keep your grey cells working.

This time, the CIA shared two illustrations that look the same at first glance and asked their followers to find all the differences between the two. The illustrations both feature picturesque red-roofed houses and trees against a dark sky. However, there are certain differences in both these pics and social media users were challenged to find them all.