Explained: How insects walk on the ceiling  

You must have seen insects walking along ceilings or climbing up the walls. While most species are unable to walk on the ceiling due to gravitational force, insects somehow manage to defy this force. Have you ever wondered how they manage to do so?  Let us find out. 

Insects stay put on walls with their tiny bristles 

Walls and ceilings appear really smooth to us. But they are covered with holes, bumps or gaps, which are not easily visible to our naked eyes. These help tiny insects like ants, lizards and spiders navigate through these apparently smooth surfaces. They are able to grab these bumps and lumps, gaps and holes using hundreds of hairs and bristles spread upon their tiny feet. This is how they stay put on walls and ceilings.  

Intermolecular forces are at play  

Microscopic hairs on the feet of insects have tiny molecules which press against each other and end up sticking together. When insects push their hairy feet against walls and ceilings, the hair molecules often stick to the molecules present on the surface of the walls and ceilings. Although this stickiness is weak, it is sufficient to keep the insects from falling off as hundreds of hairs stick to the wall. This intermolecular force helps insects stick to any surface, be it wet or dry, smooth or rugged. 

Gravitational force is weak on insects 

Insects are comparatively smaller and lighter than most other organisms, which is why they also have a lower gravitational force acting on them. As a matter of fact, the stickiness offered by the intermolecular force is more powerful than that of gravity. This is what makes it possible for insects to hold on to walls so tight.  

A glue-like substance tightens their grip  
There are certain insects which also produce a sticky glue-like substance formed out of oil and sugar secretion from their bodies. These substances are especially localised near their hair strands. This gives them the required stickiness, preventing them further from falling off the walls and ceilings. In fact, if you observe very closely with a magnifying glass, you will find tiny, greasy, glue-like footprints in the area where the insects have walked. Also, most insects have claws at the edges of their feet, which further tighten their grip.