Thank you all for the recommendations and advice!
I've unplugged the UTH for now, and will be heading to the store soon to see what I can find from what you've all mentioned.
I guess my biggest concern with the substrate was his first strike was the equivalent of chomping down on a vertical tooth pick. Gave me chills just thinking about it! I guess I can give the cardboard box trick a try and see how well it goes. Otherwise I'll look into the newsprint as well. I saw a thread with a link to unprinted newspaper I could try.
Thanks again! I'll most likely be back with more questions about the new, little guy.