Just wanted to share my expierence. I keep my dubia in a steralite tub with a UTH on the bottom of one side. About 3-4 weeks ago I moved my UTH from the bottom of the tub to the top middle. My colony really took off and started growing at a quicker rate. The dubia usually stay up higher now so their waste gets caught in the egg crates a little more but I just tilt them around and it falls to the bottom. I also keep my lobster roach tub on top of it so it's kinda like a 2 for 1.