The animals use different techniques to climb walls and walk upside down on the roofs of houses or on a wide variety of surfaces, such as leaves, trunks and tree branches. To overcome the force of gravity, some insects, such as cockroaches, rely on tiny and numerous claws located on the tips of their legs. Others, like slugs, use an efficient microsuction system. There are also those who, like flies, have microscopic adhesive “pads” on their feet, which cause a grip similar to that of walking with a piece of chewing gum stuck to the sole of your shoe. Check out how these and other mountain climbers manage to perform their feats – and, of course, if there aren’t any of them right above you! 😀
SUPER WINDOWS
The secret of climbing slugs and snails lies in the anatomy of their “foot”, which works as a powerful suction cup. “Foot” is the name given by scientists to the lower part of the animal’s body, which is in contact with the surface. The edges of the foot are lower than its inner part, creating a kind of vacuum in the central region, which makes the animal stick together. In addition, near the mouth region, these animals have a gland that releases mucus to facilitate its sliding. This mucus further enhances adhesion.
CLAWS OF THE TIME
The adhesion of most insects, such as ants and cockroaches, is due to the presence of adhesive “pads” at the end of the paws. They are called arolium (when there is only one per paw) or pulvilo (more than one). In addition, these animals have tiny, pointed claws on the tip of their feet. Acting together, the claws and pillows allow the animal to overcome the force of gravity and walk upside down everywhere!
STICKY LIQUID
Flies manage to stick to the ceiling and walls thanks to a system very similar to that of ants, which combines the adherence of sticky pads and the use of little claws present on the paws. Some species, however, have a third device for climbing: special hairs on the end of the legs. These hairs secrete a sticky liquid, made of oil and sugar, which ensures complete attachment to the surface.
ATOMIC FORCES
Geckos and spiders use the same technique to walk on ceilings. Its paws have thousands of keratin hairs known as setae. They have a very fine diameter, equivalent to a tenth of a hair. Each setae, in turn, has hundreds of tiny endings. These ends cause electrons to shift between their own atoms and those on the surface, creating a physical attraction known as the intermolecular Van der Waals force. It is she who keeps the animal glued.
AND WHY DON’T SPIDERS STICK TO THEIR OWN WEB?
Because they know where they step. Contrary to what many people think, not all strands of a spider’s web are sticky. This feature is unique to spiral wires – the spokes and frame wires are not coated with glue. Thus, the spider always moves over the non-adhesive threads. And even if she accidentally steps on a sticky thread, she won’t get stuck. Its paws are equipped with hair and claws of different shapes and sizes that help it to get rid of the wire.