How Can Insects Adhere To Surfaces That Are Vertical?

Insects, including houseflies, amphibians, and reptiles like tree frogs and geckos, have the unique ability to walk on and cling to smooth surfaces such as walls, glass windows, and doors. This is due to their light weight and their climbing ability, which is directly proportional to the surface. Geckos, tree frogs, spiders, and insects share a special skill of using adhesive pads on their feet, which are “wet” feet. They can also use claws to climb on surfaces, making them able to use smaller footholds, such as tiny imperfections or bumps in a surface that we can’t even see.

Some insects have specialized feet that enable them to defy gravity and walk in places that seem impossible to cling to. Stiff hairs, natural adhesives, and large claws all play a role in how insects cling to surfaces of different properties. On rough surfaces, insects can employ both their pads and claws to help them attach. However, on smooth surfaces, claws become more effective.

Insects have microscopic bristles on their legs, which allows them to cling to irregularities on the surface. Even surfaces as smooth as ceilings are attached to insects using a “van der Waals force”, where tiny molecules, such as those in the microscopic hairs, produce a glue-like substance that helps wall-climbing insects walk upside-down. Scientists have discovered that when upright, stick insects don’t stick but deploy special hairy pads designed to create huge amounts of friction.

In conclusion, insects possess an intriguing ability to walk on and cling to smooth surfaces, unlike humans who rely on friction and grip to maintain balance and move on surfaces.