I spent the winter carving formicaria for my hibernating ants, but they're all way too big for my colonies, who are all essentially still founding. So I've been making some tiny ones, just a cave at one end of the outworld really. There's a cave entrance at the back, leading to an ear, thence into an eye, along the mouth, and round to the other ear and eye. The idea is to be a dry cave for the pupae, but you can hydrate with drops of water on the grass hair for eggs and larvae. Probably inspired by Japanese culture, like Shadow of the Colossus. I might do some with more open mouths, to have another chamber.