Final answer:
Insects like water striders are able to walk below a thin rod on the water's surface due to the surface tension of their feet. This occurs because the cohesion among the water molecules creates a surface film that can hold light objects. Specialized structures on the insects' legs distribute their weight and prevent them from sinking.
Step-by-step explanation:
Some insects can walk below a thin rod due to the surface tension of their feet. Surface tension arises from the cohesive forces between liquid molecules, which creates a sort of film at the liquid's surface, strong enough to support light objects. In the case of certain insects like water striders, their specially-adapted legs spread their weight over a larger area, preventing them from breaking through the water's surface.
Insects cannot walk on water through capillary action, specialized leg muscles, or hydrostatic pressure. Capillary action refers to the movement of water within narrow spaces against gravity, and is not related to an insect's ability to stay atop a body of water. Similarly, specialized leg muscles and hydrostatic pressure are factors that allow insects to move, but do not contribute to their ability to walk on water.