This viral bird puzzle has been confusing people online because it looks much easier than it really is. At first glance, most viewers count the large green birds and stop there. Some go a little further and notice a few smaller birds hidden inside the bigger ones. But very few people spot the full total.

That’s what makes this puzzle so tricky. Your brain naturally locks onto the biggest and clearest shapes first, which means the smaller birds and hidden details are easy to miss. A few of the larger birds contain smaller birds within their outlines, and the two trees also hide extra bird shapes that many people completely overlook.

This is why people give different answers like 9, 12, or 15. But if you carefully count every visible bird and every hidden one, the correct answer is 21.

Puzzles like this are a fun way to test attention to detail, because the answer is right in front of you — but only if you take the time to really see it.