I have duct taped the outside of a tub for my Dumerils at one time. He wasn't wanting to eat and it helped a lot. I actually installed curtains on the front of one of my racks in the hope it would help with some of the problem ball python feeders. It helped a lot also! Most of my largest BPs are in a home made rack with black concrete mixing tubs, and I never have a problem with them. Honestly I have most of my feeding problems with the BPs in vision tanks. I have learned to cover them with a towel first thing in the morning of feeding day, this usually solves the problem.