Small, silent craft with lights goes invisible.

I have actually seen a few of these before. I see them all over no matter what state I am in I eventually find one, or they find me. They appear to be small drones that, when noticed or finished with the gathering of info, activate an active camouflage. I say active mask due to the fact that when they disappear from sight the light can be observed bending around them rather than just vanishing. They fly relatively low to the ground and can be seen at night or day. I assume most people dont see them because they dont pay attention. Other times I feel as if they are watching me in particular, keeping tabs on me for some unknown reason.