I'm interpreting your point (and apologies if I'm getting it wrong) as humans doing infinitely more complex things to process materials to build structures. Where as animals rarely process things and when they do, it's way more simple. If I'm representing your point correctly, then my response to that is that it doesn't matter how simple or complex it is. Cause if it matters, that would imply that the degree we consider animal behavior natural depends on how complex it's manipulation of building materials are. In other words, some animals would be "less natural" than others.
What im saying is that from basic huts for shelters, to fire, to the wheel, to shaping metals, blacksmiths, welding, semiconductors, etc, etc. Is all a result of our evolution within nature and is therefore natural.
Wish I had a nice whip to ride around in... 
Me: it's not the same, theres a different tartness to the ones in the bag
him: tell me where they at
me: hold on, I'ma draw a map for your dumbass
him: I found them, I got you TWO bags
: hurry up and come home...dont forget my publix sandwich too
He got two bags of sliced red apples omfg