Critter Cages are placeable decorative furniture items that display animated critters. A critter caught with the Bug Net or Golden Bug Net is combined with a Terrarium to craft a cage. All Critter Cages cannot be opened, broken, or crafted back into their ingredients, so once a critter is crafted into a cage, that particular critter can no longer be released.
Each Critter Cage type has its own dimensions and requirements to be placed:
Cages are 3 tiles wide and 2 tiles high.
Jars are 2 tiles wide and 2 tiles high.
Bottles are 1 tile wide and 2 tiles high and can only be placed below other blocks.
Both the Baby Ghost Bell Jar and the Twinkler in a Bottle emit light when placed and count as a housing light source.
Bloodworms are the only critter in the Calamity Mod that do not have a Critter Cage. This is because Bloodworms mimic Truffle Worms, which only received a Critter Cage in Terraria 1.4: Journey's End, which the Calamity Mod is not compatible with yet.