Here is why elephants have large ears.

 

We note that violins, which are small, produce high-pitched sounds, and basses, which are large, produce low-pitched sounds. The large size of the elephants’ ears permits them to hear sounds much lower than human ears. These low-pitched sounds can travel over large distances.

 

Conversely, the small sizes of insects means that they can see smaller wavelengths of light than we can. They can see ultra-violet, but cannot see red. In addition, the reason insect eyes are compound is because of their small size relative to the wavelength of light.

 

See Big things make deep sounds.