Yes, I struggle with this terminology. I actually used smallest in terms of those species that we do not recognize as contributing to the food web. We humans are, of course, only one species, and nature is still trying to balance our contribution.

Within the species, we have dual continuum of capability. The one is the continuum between infant -> wisdom. The other is between having no control of resources -> having lots resources that we control. Smallest is not the right word for these intra-species continuum. Least may not be the best word for those lower on the two continuum. - Don't know of a better one though.