Im not quite sure what you are asking. If you have too many animals for the space you have then a rack is the answer maybe?? As for your BP liking to climb, he will climb if something is there for it to climb on, but it may not be good, as they are quite clumsy off the ground and could injure themselves. The cages should not be a fire hazard if everything is setup correctly and wired correctly, and everything is kept clean and you have nothing chewing wires or water coming in contact with them.