Gergely Dudás has mastered the art of the hidden image puzzle. The Hungarian artist, who goes by the name Dudolf on the web, is famous for his Where's Waldo?-style brainteasers that embed camouflaged objects into playful illustrations. His latest scene is one of his most challenging creations yet.

The picture below shows dozens of brown squirrels crowded into a tight frame. If you study the image closely enough, you'll notice that one of the squirrels is actually a mouse. Like all of the hidden images in Dudolf's puzzles, the mouse is designed to blend in with its surroundings, making it almost impossible to spot at first glance.

If you've been staring at the image for a minute or two with no luck, here's a tip: Check the ears to find the animal that doesn't belong. And if that clue doesn't prove helpful, scroll to the bottom of this webpage for the answer.

Dudolf has created visual brainteasers for every time of year. After completing the puzzle above, see if you can find the ghost among the rabbits, the sheep in the Santa Clauses, and the heart in the snails.