I WONDER - What Is Special About A Gecko?

Geckos possess a unique ability to walk on walls and ceilings due to tiny hairs on their feet called setay. These hairs interact with surface molecules, creating a strong adhesive force similar to microscopic suction cups, allowing geckos to stick to surfaces without using sticky substances or applying pressure.

What is the effect of the microscopic suction cups on geckos' feet?

What do geckos not need to stick to surfaces?