A bird cage is a confinement for birds, but there are several other synonyms for this word. A birdcage may also be called an aviary or a birdhouse. A cage in which birds are kept can also be referred to as a bird enclosure, a bird coop, or a bird house. Furthermore, it can also be called a bird pen or alternatively a bird sanctuary. Regardless of the name, it is crucial to provide a comfortable home for birds whether it's in a cage, an aviary or a larger bird enclosure.