Once upon a time, this was an experimental thing. I am no longer working on it. One of the chamber blocks fits in the main housing to create a small formicarium large enough to contain a young or small colony of ants. ~ A 1/8" thick piece of acrylic or clear plastic is needed to complete this piece. The dimeio are 1.633" X 2.212". If you only need one piece, visit and Contact Us to inquire if plastic pieces are available. ~ Development for this project has been suspended, and the models will be deprecated by a forthcoming design.