Hungarian artist Gergely Dudás creates mind-boggling brainteasers containing hidden objects or details and challenges the internet to find them. He’s released three books of brainteasers: Take a look at the brainteaser below:

One of the holiday puzzles is called “Bear’s Merry Book of Hidden Things,” a Halloween-themed book called “Bear’s Spooky Book of Hidden Things,” and his latest, “Bear’s Springtime Book of Hidden Things” and others.

In past Christmas-themed drawings, Dudás has hidden Santa’s hat among striped hats, a snowman among snowflakes, and a card among gift bags. In this holiday brainteaser, there are seven hidden objects:

Riddles that challenge us to spot differences between 2 similar images activate our concentration power to the maximum: they put our eyes and brain to work. This is great because training our minds is as important as exercising our muscles.