Grizzly always like to run around and popcorn while I clean the cage. Usually he just watches me a bit, then popcorns off to the side. Or runs under the handle of the dust pan while I'm holding or. Or of course does his laps on the other side of the cage.
But once in a while he popcorns right on the pile I'm sweeping. I think he just wants me to notice how happy he is about my cleaning.