What symbol from nature does the poet use to prove that 'Keeping Quiet" is not a total inactivity?

 What symbol from nature does the poet use to prove that 'Keeping Quiet" is not a total inactivity?

The poet employs an image of nature to prove that under apparent stillness, life is what it is about. The earth is always active. In winter, it seems that life is waning and shrunken, as nature loves her colour and charm. Trees are without leaves, the north wind roars; the animals hide, the waterbodies freeze and the flowers refuse to bloom. A dead silence prevails all around. But life does not come to a dead stop, for, winter is followed by spring. "If winter comes, can spring be far behind?" With the advent of spring nature looks vibrant and lovely again. So the apparent calm does not mean total inactivity or death. It is just the preparation for getting a new life with new hope and freshness.