You can do like I did, when I changed over to sand, I put the decorations in first, and then the sand. This way if the horeshoe bumps into a rock, he can't knock it over. If the rocks are on top of the sand they keep diging under causing the rock to fall. I think they are cool, and as long as they have food to eat, go for it, they will kill all the critters in a live sand bed. I haven't seen mine now for a month!!