Sounds like your peacock is simply rearraging his digs. Ours was constantly busy with "improvements", so every so often, we'd drop in a few bits of rubble or some shells. It blew me away to see him using his antennal scales as oars to move heavy pieces. Ours had a mussel valve it used as a "door", and it would prop it up to the side of the opening to its lair so it was within easy reach.
Monsinour,
Yes, they will rebuild, but not necessarily the same way. We knew someone at one of our LFS that would scatter his peacock's lair just to see it rebuild.