I have only one top bar hive. It overwintered as a small 8 bar colony and has started expanding and drawing new comb. I have been moving the backer one bar at a time and shifting the last comb to add a new bar in the empty space as they go. The hive is about 1/2 drawn out. Should I continue leap-frogging the bars or place the backer more toward the end giving them plenty of room to expand? If they continue to build is it a good indication that they are unlikely to swarm?