You know what I think would be dope? if it was three(4 technically) separate pieces. The base with an exit to whatever outworld you put the nest in, the nest with an opening in the top and bottom, a plug for the top opening and the cover. The bottom exit would lead to the tunnel in the base allowing them into the outworld. That way you could just print/buy the nest piece and expand the nest upward to give them more nest space. No idea how hydration or telling when your colony needs to expand would work, but I like the idea.
I think it would be good if you can add extra 'slices' to expand the nest upwards so an extra piece can be added each time the colony needs more room, that way it can be expanded indefinitely and never need replacing no matter how much the colony grows.