built my racks and offered hides to some ( taken them out recently to be cleaned and keep forgetting ot place them back in ) but everyone doing ok without them. but then my racks are only open in the front, the sides and back are solid since i used plywood to build mine. I made hte rack large enoug hthey can take my tubs with the lids on and locked as well as wider ( if I ever can find a tun that less than 7 inches tall ) I can move the rack center support or when I rebuild the shelves with heavier plywood to prevent sagging no dividers.. Before you build, get the tubs and such ( or th hides) consider ifthey fit into the rack or the tub with out pushing against the top or casue a gap that the snaek might to squeesze though. ( reason I like my lids on they an top they can't get though and still have some space incase I need to pull it out and not hurt the snake if they got stuck trying to get out as the lid would be against the wood and not the snake .