With a towel draped over the cage, he will be calm and quiet. The wild ones don't howl. That is something the tame ones learn as a way to communicate with us and get our attention. With the towel, it is like a little cave. He will be fine.

I was going to say a trash bag, then some old towels but I see someone already did that.

I usually just line the inside of the trap with newspaper. I leave them inside on the futon, and I've never had a problem with them going through; beginner's luck I guess! As if a couple sheets of news paper would do it!

Best of luck.