If the bin is totally smooth climbing shouldnt be an issue. Also what is a fairly large colony? Some people think 1,000 is a large colony. Roaches like to be in close contact with each other. They dont like a lot of elbow room. If you notice they are all in a clump with a lot of empty space the bin is too big. We do not use such high female to male ratios. it is better to just have large numbers of roaches than to have an inordinate amount of female to male ratio. A pound of roach food will last until it is gone or it spoils. Keeping them heated and dark will make them more active thus eating more.
Digby Rigby _______________________