Tiny Dancer Spider

As I was working on my computer a tiny spider (3-4mm) dropped down in front of the screen then scurried back up its invisible silk lineagain. 
I wondered if I really saw it, or maybe it was a hacker's April Fools joke.
Then down came the tiny spider and back up again.
I realized it was trying to spin a web.
After multiple downs and ups it stopped (rather anticlimactically)  and I got on with what I needed to do on the computer.
I'm glad I thought to capture its  on-screen high-wire act shenanigans with a photo as the whole incident seems a bit surreal in retrospect.