Why do geckos stick to walls and ceilings?

Question

But the answers can't be suction or friction.

Answer 1

they live in my garden and run up the garage wall. if you can catch one, which is a feat in itself although my cat can and then eats them, they have really long claws thats how they do it.
in the summer we get them in the house sometimes and on a tiled floor they are like a dog on lino...

Answer 2

It's actually a problem that has vexed scientists fora while, but now is well understood.

The stickiness of a geckos foot pad is due to Van Der Waals forces, the same attractive forces that are responsible for surface tension in liquids, etc. The foot pads consist of very specially structured hair-like loops that have nanoscale "feathers" if you will. These nanoscaled (100 nanometer and smaller) structural features allow the "hairs" of the foot pad to have a large amount of surface area, so that there is a lot of contact area for Van Der Waals forces.

Van Der Waals forces fall off rapidly with distance (they are proportional to distance to the -6 power). Thus, if you want to have something that works via Van Der Waals forces, you have to be able to position the surfaces to within VERY close range (100's of nanometers at MOST) overa large area, and that is why the unique nanoscaled structure of a geckos foot pad allows it to do what it does so well. All other solid-state substances known also experience Van Der Waals forces when in physical contact, but surface roughness prevents the actual contact patches from having much surface area. Thus, the geckos foot has solved this by allowing a way for surface roughness to be overcome.

Answer 3

The bottom of there feet are covered with tiny microscopic stiff hairs that they can control. This allows them to "grip" the very smallest of surface irregularities which almost all walls etc have. The effect is somewhat akin to Velcro with the Gecko having the "hook" part.

Answer 4

no suction cups! (no glue the two) merely lamellas with very advantageous hairs that are chop up extra into even finer (invisible) hairs - Justina and crazyottto are precise. I actually have a gecko, additionally eye-catching pictures have been in between the final themes of the nationwide geographic magazine

Answer 5

Scientists have discovered that geckos have millions of microscopic hairs on the bottoms of their feet that somehow allow them to stick to surfaces.

Answer 6

They have a gooey solution that allows them to stick. Its on their body

Answer 7

Maybe a better question would be how do they catch the mosquitoes.