Actually I been keeping the hermies mostly in the upper unit and no one in the lower unit while the sealer is drying. I also have kept the top off (well sitting at an angle) so it will vent while it dries and get fresh air in and help in drying. Right now everything is happening all in the upper tank for a few days. I had some of those wooden hut / caves previously.. had a little but die for no reason that could be found. He was just hanging out of his shell. Someone said probably mites... SO I did a deep clean and deloused all the hermies just to be safe. I read on this site somewhere that anything wooden is where mites like to hide.. so it all got tossed. As far as the hernies and escapes...no problem there. I cut a 4" by 4" hole in the bottom of the top tank. Now I also set the top tank on a piece of plywood for support (and the plywood also helps keep heat in the lower tank. Of course I have a 4" by 4" hole in the exact same place in the plywood that matches the top tank. The top tank sits flat on the plywood.. so no way a hermie can find a way out. They seem to love it.. gives them more things to climb on and the extra tank gives them more places to go. I also added some cargo netting in the lower tank for more climbing 'stuff'.