I realize you are reading this from a random person on the internet, but for what it's worth this is 100% truthful. This happened a few years ago. The footage came from my Foscam 480p IR cam and was recorded with the android app IPCamViewer.
Here's the whole story.
One night I was standing outside in my backyard at about 2AM with my girlfriend, smoking a cigarette. I was sober and sound of mind, at that time I didn't drink at all. I typically stayed up late because of my masters program homework and my girlfriend got off work late.
It started as a chirping sound, which I remember sort of laughing and saying to her "what the fuck is a squirrel doing awake right now?". The sound was coming from the tree which was directly in front of us about 15 feet away. This tree was about 25-30 feet tall and the noise seemed to be coming from about half way up. As I started to walk toward the tree in an attempt to see the squirrel, the noise began to move sideways, out from behind the tree and into the open air. Despite this, I could not see anything creating the noise and the pace of the sound began to change, and the chirping began to increase in frequency. At this moment I figured it was a weird bird that I was unable to see. Then the sound changed again, louder and much quicker chirping. It was a this moment I realized it was not a squirrel or bird making the noise, maybe its a badass drone. This whole time I am tracking the sound with my ears and looking where I think it's located, but cannot see anything. Then suddenly, right where I've been looking I see an incredibly white and bright sphere (about the size of a volleyball) right in my vision. The sphere suddenly slams into the ground on the other side of the fence without a sound and I can no longer see it at all. That is when the noise I will forever remember as "the click" started. It was a sound unlike any other I've heard, and I've worked around a lot of machinery, have my own drones, etc. I still can't think of anything that properly describes this sound. The sound was irratic and I will admit it, it scared the shit out of me. So I grabbed my girlfriend and pulled her into the house, slammed the door behind me. I grabbed my phone, pushed record then went back outside and sure enough, that noise and whatever was emitting it was going back and forth across my backyard. You can listen to that sound file here: https://www.dropbox.com/s/tv6r33hrn3um98y/TheClick_Short.flac?dl=0
The next day I decided to place my Foscam 480p resolution infrared camera near me when I was smoking to perhaps help spot anything to explain the previous night. That night when going for a smoke I noticed there was what initially looked to me like the dot of a laser pointer only white (because of the infrared camera). I pressed record on the android app "IPCamViewer" and tried to make sense of the situation. When I first step out from the doorway where I was having a smoke, you can see the object literally hide from me by moving up and to the right near the top of the umbrella, then cautiously return. It looked like the dot was on the wall, but you can see me place my hand in between the wall and the object in question. I then look directly at the object to see if I can see it with my naked eye, I could not. There was no sound at all this time. After realizing it was not something I could see I decided to give up and head inside to look at the footage.
There are a few things that I noticed. This "device" had what looked like a very small antenna on the top of it, which it was able to maintain perfectly straight upwards, despite the wind and its own movement. This antenna you can see extend longer and longer towards the end of the video with two or three horizonatal lines running perpendicular to the antenna. I refer to it as an antenna but it could just as easily, and perhaps more reasonably have been a sensor or weapon.
For those that think it might be a bug? There's a spider between the object and the camera in the video. Typically bugs not only show up silver or grey, but you can usually see legs wings etc. This object is white. Bugs also do not behave like this object. You may see a line in the top right, that is the moon's light reflecting off of the object. If it were a spider web, it would flex with the wind rather than remain completely ridgid despite where the object moves.
I also uploaded more videos from the same camera to the same youtube channel. You can see me and some friends try bugs, dust and other tests.
Here's the video: https://www.youtube.com/watch?v=CdB-Ze_R2Uo
This is where we take a slight turn in the story away from ufo's/aliens/probes.
I tried many times to catch that object or one like it on camera, but was never able to capture something like that again. If your curious you can look at the other videos on that youtube channel SentientExperiment. However, because I did continue to record and upload footage from my cameras, I was able to discover something else in the infrared light spectrum. Since my cameras were pretty outdated I ordered a new one from Amcrest and it clarified my suspicion about the infrared light spectrum. If you look in the 940nm infrared light spectrum with a camera with enough resolution (at least 760p) you can clearly see what I like to call "air-squids" flying about. On a 1080p camera, you can not only see the wings of bugs, you can see their legs and antenna and a great deal of detail. You can also see these squid-like creatures zooming around that ordinarily would be dismissed as "dust or bugs". But if you look closer you'll actually see they never collide with anything, not eachother and not the environment, ever. They also appear to have 3 appendages or tails that trail behind it which may or may not be providing propulsion and steering. Much like squid, these air-squids will also flash different shades of white (probably white due to being viewed in infrared) at varying frequencies. I can at any point during the night, look at my cameras and see at least one air-squid.
Here is a short video of that, you can see one best at 00:16: https://www.dropbox.com/s/yqj6ptomp0hyiff/20161214_181514_20161214181516_20161214181544.avi?dl=0
Are the two related? I don't think so, they're very different in behaviour and composition. But it does go to show you how little we know of the other light spectrums and that's just infrared.
In summary, I highly recommend you take a look for yourself, with your own cameras. I can't guarantee you'll see the device I described, but you will definitely see the air-squid.