Blush is a very important organ of the house. Regulates the temperature and keeps it warm and alive. Blue when cold, but blushes with red when warm.
The radiator, painted with thermochromatic paint, gradually turns red from top to bottom when it is heating up.
Also, The Devil's Pet:
Sweet little kittens are transformed in a fire. Crawling from the ashes come forth grinning metallic devils with sharp claws and fire blazing in their eyes.