According to this article these young crustaceans have already spent 10 to 14 weeks riding around in the pouch of a female Pillbug. I wonder if we could look back at previous video and identify any of them?
The area represented in the video is approximately ~8.1cm x 4.5cm (3.2" x 1.8"). This puts the young Pillbugs at ~1.5mm (1/16") in length.
Most of the Pillbugs quickly disperse beyond the viewable area within a few seconds. A few slow down and some can be seen feeding, or being fed on.
So much happening in such little space, so much more happening that's barely visible, and I can only begin to imagine how much is going on that isn't visible at all at this level.