Does Han Yu really think that crocodiles can understand and listen to him? Is it true that the crocodile gradually disappeared after writing?

I think: 1. Sacrifice crocodiles to break people's superstitions. 2. By the way, express your loyalty to the emperor (perhaps a little ironic). 3. There is also some depression (being demoted). 4. By the way, scare the local evil forces.

According to textual research (tested by others), 1. The crocodile did disappear. Setting off firecrackers, killing people is part of it. It is said that climate is the main reason.