Having the right camo on, along with being very diligent about not moving hardly at all, and picking your spot so the winds doesn't blow your scent across their trail/pathway into your FOV allows you to take a sit in a spot without a lot of natural cover to hide you visually. It allows you to have those intense encounters like BOWUNTR described of them staring directly at you and "burning a hole thru you" at distances where you could hit'em with a rock! It's bad-ass when those encounters occur!
Or instances where they are walking by soo close... that you actually have to let them walk slightly past you before you draw your bow or raise your rifle, so their eyes don't see it and they spook/run.
And yeah... hoomans are the worst... they'll walk past ya all the time... even look right over in your direction and not realize you're there.
Was on a set for predators with eCaller and motion decoy, this hiker/trail-runner looking kinda dude, late 50's.... he comes up.. when he hears the caller and sees the motion decoy...get this... he stops...he raises his hands high into the air!... then slowly turns around with hands still raised... and starts going back the way he came, eventually lowering his arms back down when he reaches the edge of the meadow/clearing. Just weird.
And then, just the other day.... I'm out in AngelesNF at a spot with Bear sign, where I've called in Grey Fox before, and we've gotten bear on TrailCam. Got the motion decoy out and hitting the mouth calls. And imagine my surprise when I called in 4 old Japanese hikers! (hehe). So bizarre. The first one walked past the motion decoy without looking at it. (They looked to be upper-mid 60's) The others notice it.. then oddly they gather around it, chattering to each other about who knows what. They begin to continue on their way... but the other dude in the group of two couples... strangely he stops to whip out his phone and freaking take pics and vids of the thing! #facepalm. None of them saw me at my elevated position above them. Four pairs of eyes.