Homophone is a word that is pronounced the same as the other one but it has different meaning. All languages have such words. Mandarin Chinese has many homophones.
Very good example is the word fú which means a bat. Fú also means good fortune. These words have different Chinese characters. The present similarity contributes to the fact that bats are considered as symbols of good luck.
Usually more than one bat symbol can be seen. Two bats or "shuang fú" means double luck. Five bats signify Five Fortunes - Good Luck, Prosperity, Wealth, Happiness, Longevity. Bat's colour plays an important role too. Chinese word "hong" means both red and vast. So, it can be said that a red bat brings vast amount of happiness to one's life.