My parrot hasn't been moving rocks that I know of, but I think this may be because her mouth is so little..... Matter of fact, she has her own special food cause she can't fit my other fishes food in her mouth!
I do not mess with my JD's holes...... Smoothed them over a couple times and each time he got pissed....... Waste of time anyways, convinced that he could did a hole big enough to bury me in 10 minutes flat......