Underside of a gecko’s foot. Those ridges are full of thousands of tiny setae, ‘hooks’ that allow these lizards to grasp onto nearly any surface, and in any orientation. Spider-Man employs a similar morphological adaptation. (at The Field Museum)
Gecko feet are waaaaaay near the top of the list when it comes to awesome animal adaptations.
But they don’t really “hook”, certainly not like Spider-Man does, anyway. Each of those setae is just one-tenth the width of a human hair and contains hundreds of tiny projections that are each less than half of a millionth of a meter wide. To put that in perspective, that means each projection is as wide as just two human chromosomes. That’s small.
Because they are so, so, so tiny, the geckos use atomic interactions and Van Der Waals forces to hold themselves on the wall. They are literally using the attractive forces between atoms to walk on the ceiling, with no liquid or adhesive to help. The , which is 1,000X cooler :)
I featured them in this video on Animal Superpowers: