Does a cat cry because it's sad?
A cat cries not because it is sad.
One reason is that cats have well-developed tear ducts and very sensitive nerves, so they may cry even when there is nothing wrong.
Secondly, the cat's eyes may tear up due to its natural eye structure or because its fur is too long and pokes into its eyes, making it look like it is crying.
Thirdly, cats may shed tears due to stimulation from foreign objects, gases, or smells. 
Fourthly, cats also have emotions. When they encounter sad things, such as the death of their owner or being sick and uncomfortable, cats will cry.
Fifth, because a large number of cats' meows sound somewhat like a baby crying, it sounds like they are crying in the middle of the night.
Sixth, cats may tear up due to eye diseases such as conjunctivitis or infectious diseases.
Therefore, a cat crying is a normal phenomenon and does not necessarily mean that the cat is actually crying. It is just a tearing phenomenon caused by various different reasons.
