How to keep feeders from getting under substrate

Hello! I am in the process of redoing my Leo's tank and I have run into an issue over and over again, no matter what I do. Currently I am using paper towels as my substrate until I get ideas about what else to use, but my feeder insects always seem to hide under the paper towels, not allowing my Leo to hunt them! Previously I had been using reptile carpet as my substrate, and had the same issue. They always seemed to find the tiniest lifted corner or little seam between the tank and carpet to get under it. My Leo does not always hunt his food immediately, so I generally like to leave at least a few feeders in overnight to give him plenty of time to eat what he wants. He does not seem to recognize food that is put in a food bowl, so this is not an option either. Anyone have any suggestions?

Make your paper towels a little narrower than the cage floor and duct tape them down.

Aliza