Not just flies, spiders, lizards, ants and other creatures too have the unique ability to walk up the wall. They are not defying gravity, of course. They simply have specialised feet that enable them to hold on to the wall without falling off. They use a combination of features such as tiny hairs, natural adhesives and large claws to carry out the task.
In the case of flies, each foot has two fat footpads that give the insect plenty of surface area that aid in climbing. The footpads are covered with adhesives produced by the insect itself. These pads, called pulvilli, come equipped with tiny bristles or hairs that have spatula-like tips. These hairs are called setae. Flies need sticky feet to walk on ceilings, but not so sticky that they get stuck upside down. So each foot also comes with a pair of claw-like structures that help remove the gooey foot off the wall. If you look closely, you will notice that most wall-climbing creatures leave behind sticky footprints. The ‘claws’ and adhesions also help the insect hold on to different types of surfaces – walls, wood or glasses.
Picture Credit : Google
