During diffusion the molecules move in constant random motion. <span>The </span>net movement<span> of a substance from a region where it has a higher concentration to a region where it has a lower concentration, due to random molecular motion, is called </span>diffusion<span>. Diffusion is a widespread and important process which occurs in both living and non-living systems. </span>
The reason why humming birds need long beaks is to be able to get the nectar from the flowers, kind of like how we need straws to drink out of to go cups. Humming birds also have very long tongues that also help this process. Since humming birds beaks help them get the food they need, it makes them more successful in their environment.
There has to be one side with a high concentration and another side with a lower concentration