Imagine being like Spider-Man and being able to crawl up walls and hang off ceilings.
Well this could come true one day as scientists have worked out exactly how spiders and other creatures can stick to a wall without falling off.
Spiders and geckos (small lizards) have loads of tiny hairs on their feet which means they can stick to surfaces.
Scientists say they've worked out how to create enough similar 'stickiness' to support a human being.
They say that all the tiny hairs on these creatures creates a kind of very sticky 'Velcro', which allows spiders to attach themselves to things like cement and glass.
But to allow a human to stick to a wall would be quite complicated.
A suit would have to be made with thousands of tiny, hollow bits on them (called 'carbon nanotubes'). The surface the human wanted to climb on would also have to be very strong to allow them to stick.
It's all a bit of a long way off, but scientists reckon it really could happen.
"Now that we are this step closer, it may not be long before we are seeing people climbing up the Empire State Building with nothing but sticky shoes and gloves to support them," one of the scientists said.