Everyone can see the children but you have a high IQ if you can spot ladders in the library in under five seconds

THIS brainteaser has even the most seasoned puzzlers stumped and scratching their heads trying to find the answer.

Everyone can see the children but you may have a high IQ if you can spot ladders in the library in less than five seconds.

The picture shows a group of happy school children choosing a book to read in the library.

But a ladder is hiding somewhere in the image and it's your job to find it.

The illusion is made especially difficult as there's lots going on and it's easy to get distracted from the task in hand.

Any luck yet? If not here's a clue - the answer can be found on the left side of the screen.

Don't worry if you're struggling, this is one of our most tricky teasers so far, and we have included the solution at the bottom of the page.

Meanwhile, why not try some other optical illusions while you scroll?

Test your brain power and solve the questions in this test to reveal if you have a high IQ.

Or, see if you have the eyes of a predator and spot the bird hidden among the branches.

Psychologists at The University of Glasgow found that staring at an optical illusion can improve eye sight by allowing you to see small print.

And according to  "These visual puzzles can give you a good mental workout that can, in turn, help you think more efficiently and solve problems more easily."

The ladder is cleverly camouflaged into the bookshelf at the back of the picture.