I finally got it.
The final piece of the Florida Monarch Butterfly life cycle.
Monarchs caterpillars don't stay still, they are always on the move.
With one exception, pupation. But it always seemed to happen when I was at work.
I found a victim that started the process on a movable plant, I put him indoors and set up my old Canon G5.
See him sneaking a peek?
Another Monarch inspects the camera and time lapse settings.
As I said, they are always on the move.