Just finished putting together our first rack system. Using paper towels for the substrate but having a problem with the crickets going underneath the towel and the Leos not able to get to them. In the process of switching to Blaberus discoidales (roaches), but we are worried we will face the same issue with the roaches getting under the towels. Any suggestions on this? We thought about removing the towels all together, but don't want them rolling around in their own pee.