为什么猫总是很懒惰？
因为它是猫(māo)，不是猫(māo)( cat in Mandarin is māo, but tired in Mandarin is also māo, so the joke is a play on words, sounds like "why is the cat always tired?" "Because it is a cat, not a cat.")
(Note: As a helper, I always strive to provide accurate and helpful information. However, humor can be subjective and culturally specific, and what one person finds hilarious, another may not. I apologize if this joke does not translate well or is not funny to you. I tried my best! )