Optical illusions have a special way of making you question everything you’re looking at. No matter how determined you are not to be fooled, your brain often has other plans. One recent example baffling the internet involves a simple photo: six girls sitting on a couch… but only five pairs of legs are visible. So where did the sixth pair go?

According to the Queensland Brain Institute, an optical illusion occurs “when our brain and eyes try to speak to each other in simple language but the interpretation gets a bit mixed-up.” The brain might think something is moving, or shaped differently, or missing altogether, simply because it’s trying to make sense of information that doesn’t quite align.

On Reddit, a particular illusion has gone viral for exactly this reason. The photo shows six girls sitting closely side-by-side, but only five pairs of legs appear beneath them. Naturally, the internet sprang into detective mode.

One Reddit user suggested that the second girl from the left has her legs tucked directly behind the first girl’s legs, making them invisible from the camera’s angle. In other words, the first girl is unintentionally “borrowing” the appearance of those legs.

Another user, however, seemed to crack the illusion entirely. Breaking it down from left to right, they explained:

Girl #1 has her legs crossed, and her jeans show no tear at the knee.

Girl #2 has only one leg clearly visible — the one with the knee tear and white sock. Her other leg blends behind Girl #1’s because they are leaning in closely.

Girl #3 is leaning heavily toward Girl #4, which makes her legs appear shifted and visually confusing in the lineup.

Once you trace the torn knee and the sock correctly, the illusion starts to make sense: nothing is missing — the legs are simply overlapping in a way that tricks your brain into thinking something is off.

If you still don’t see it, don’t worry — most people needed the breakdown to finally understand. Optical illusions play directly with the shortcuts our brains use to interpret the world, and this one is a perfect example of how easily we can be fooled by perspective and positioning.

Share this with your friends and see if they can figure out where the “missing” legs are hiding — it’s a fun little puzzle that reveals just how powerful (and occasionally perplexing) our minds can be!