By that logic you can say anything is natural (like the weasel-words on products that say, 'all natural' -
everything is, technically, natural!
But I get what you're trying to say. I still believe that when we began glomming together out of our proto-primitive state, for shelter, security, and sustenance, that we began to engage in a variety of non-instinctual behaviors, including pet-keeping! The example of ants 'milking' aphids is pure exploitation, essentially - not pet keeping as I see it. There are other examples of parasites living on larger insects by hollowing out cavities in their hosts brains - whose keeping whom? Macabre! haha...
Which is fine - if humans had stayed 'natural', we'd be no different than animals. Those societies that continue to live on the fringe of modern society - Inuit, for example - I think are the most close to nature, but there are
no humans left living in a natural state. Or if there are, we call them apes

We, just like all other animals are bound by the constraints of our nature and do very little that is not in accord with our natural drives. Our denial of our rightful place in the natural world does nothing beneficial and only serves to lesson us as a source of support in the natural world all around us.
Also, we have no 'rightful' place in the natural world, anymore than mice or parasites or mosquitoes have a 'rightful' place - what's 'rightful' is whatever niche a species has carved out for itself. We decided we have a 'rightful' place at the top, having achieved that spot through mass-breeding and expansion. History is written by the victors and all! We'll never know what other (formerly) apex species think of the 'rightness' of our place in nature, nor does that really matter. I think when human expansion first began, we did in fact do very little not in accordance with our basic, natural, instinctual drives. Now, though, here we are on a forum, typing away! I'm not hunting caribou later, anyway.
All the species over time that went extinct (excluding human intervention and cataclysm) had no 'rightful' place - they unluckily did not breed and mutate (re: evolve) enough to survive. Since we stopped significantly physically evolving evolving ages ago, we adapted the environment instead, hence claiming our "rightful" place.