The bat is considered an auspicious classical Chinese feng shui symbol for prosperity. However, one could say that the symbol of the bat is rarely used in the Western world feng shui applications.
As you know, feng shui symbols are deeply connected to the culturally specific symbolic level, which means you would choose a symbol as a feng shui cure according to the meaning it has for you, not according to the meaning from feng shui books.
Interpretations of symbols are always a complex endeavor, as it all depends on the culture you grew up in or the culture you feel most comfortable in.
In classical feng shui applications, Bat is considered a symbol of wealth and used as a wealth cure because of the same word/pronunciation for Bat - "Fook" - also means "Prosperity" in Chinese. Bat also came to represent happiness and longevity, so it is an auspicious symbol in Chinese culture.
Here is interesting info from the creators of FengShuiBestBuy.com, one of the largest on-line feng shui retailers: "Bats have a legendary role. In caverns of the hills in China are found bats of a thousand years old which are silver-like is color and are fed on stalactites. These bats have medicinal values and are an important ingredient in Chinese herbal medicines. They normally appear in the summer to bring happiness and are torpid in the winter. Because of its ability to swallow its own breath, it attains a very long age.
The symbolic presence of bats is employed in many Chinese homes, used together with other fortune symbols to signify wealth."
What does the feng shui symbol of a bat mean to you? Does it speak to you of prosperity and good fortune? Be wise when it comes to decorating your house with various feng shui symbols.