Simon is an active sleeper.

I heard scratching on plastic and went to investigate.  I found Simon "running" in his sleep and I think he did a move similar to a "binky of joy" judging by the zone of clearing around his head and back feet.  Bunnies definitely excel at napping to the point that I think the phrase, "Sleep like a baby." should be replaced by "Sleep like a bunny."
The first few times we saw Simon and River sleep like this and not move, we would check to see if they were still breathing.  The full-on lop flop nap scenario was a shock because we'd never had a bunny that slept like that before.  Nice to see they were totally unaffected by our panic.