Animals play an equal role in the process of erosion and also contribute to the weathering of the earth's and thus are an active agent of mass wasting and hence are important factors that influence the process of erosion.
The animals dig out the earth and bring air and light to the deeper layers of the rocks and thus expose the rocks to greater depths, and hence influence the carbon, oxygen and chemical cycles if the planet.
Immigrants are willing to do the jobs that Americans won't do, for wages that American's would not accept. They take the jobs that Americans don't want.
