vivarium: an indoor enclosure for keeping and raising living animals and plants and observing them under natural conditions
enclosure: a structure consisting of an area that has been enclosed for some purpose
musical chairs: a child's game in which players march to music around a group of chairs that contains one chair less than the number of players; when the music abruptly stops the players scramble to sit and the player who does not find a chair is eliminated; then a chair is removed and the march resumes until only the winner is seated