If you don't listen to night bugs, how can you know how to save things?

The sentence "How can we know the existence of things if we don't listen to insects at night" means that we don't know the changes of seasonal climate if we don't listen to insects at night. The "night bug language" here can be understood as the sounds and hints of nature, which makes us feel the changes of the surrounding environment.

This sentence enlightens us that we should always pay attention to the changes in the natural environment and the surrounding ecological and meteorological information in order to better adapt to nature and live in harmony with nature.

At the same time, it also reminds us to pay attention to details and observation, and get information and enlightenment from subtle changes, so as to better grasp the opportunities and challenges in life and work.