Looking around more closely I saw the object of it's interest.
An unsuspecting brown moth was the spider's target.
Eventually, the moth realized it was in danger and fluttered away to another part of the screen. The spider doubled back and slowly worked it's way to the moth once more.
The spider was an experienced hunter because it was slowly sneaking up on the moth. Then when it was close enough to the moth, it quickly made it's move and attacked the moth. Before the moth knew it, it was in the jaws of the spider.
The moth put up a good fight but was out-matched by this persistent adversary. Looking more closely I realized what kind of spider it was. A black widow was holding on to it's prey and wasn't letting go. I was thrilled to catch mother nature at work on camera. A once in a lifetime event!