How humidity makes gecko feet stickier: Softens setae to tighten gecko's grip

ScienceDaily (2010-10-17) -- Geckos have amazingly sticky feet. Their stickability comes from billions of dry microscopic hairs that coat the soles of their feet. However, when humidity increases, gecko feet stick even tighter to smooth surfaces, so how do they do it? Biologists have found that increased humidity softens the keratin that makes up the sticky foot-hairs, allowing them to deform and stick tighter to surfaces than hairs in dry conditions.