Personal confirmation that UFOs cloak themselves and could be in our skies at any given time of day or night.

Around the age of 14, I was across the street from my house, in a vacant lot. I was picking up rocks and hitting them with a beat-up baseball bat. I bent over to pick up a rock and I noticed a shadow moving directly between my legs. It was a triangular formation of 6 perfectly round circles moving at about 5 mph. Shocked to see such a shadow, I looked up to see what was in the sky above me. There was nothing (no birds, no clouds, no planes; the sky was all blue and they weren't sunspots because I was not looking up until that point). I started to follow the shadow, looking back & forth from ground to sky. I followed it for about 20 yards until the end of the property. This was not my imagination, nor was I under any influence. These objects were casting a perfect shadow on the ground, but were totally invisible to the naked eye. I felt it was important to send you this because I've never heard of anyone reporting such an occurance, although I have heard speculations & reports on UFOs disappearing and then reappearing in a different spot.