I'm finishing a 4.5 foot tall lizard cage. It's going to have lots of natural dirt, logs, leaves etc. I'm going to have roaches and bugs living inside and don't want them to be able to climb up into the lighting or out lighting holes in the top. Is there any paint or something I could apply at the top that's slippery enough to keep them from climbing it? I can make it sealed with screen vents if needed, but would rather not.