my second wife, not embarrassed to say that anymore, had a terrarium at her grandmother’s place which she lived during her childhood. she had 2 actually. One was a plant terrarium and one was for shrimp. One shrimp lasted over 20 years. Had to clean the egg shaped glass with a magnet. that’s not a metaphor to the world. her shrimp house was egg shaped and only 6 inches tall. no food was ever given to it. lived for over 20 years. A magnet cleaned the outer edge of the glass encasement. enclosed system.