What are some symbols in "The Birds" by Daphne Du Maurier?

In "The Birds," Du Maurier employs a number of symbols. Here are a few to consider:

The gun symbolises how man underestimates the power of nature. Mr Trigg thinks that shooting the birds will be fun, for example, and will solve the problem of the birds' attacks. But, as Nat predicted, guns are powerless against them. In fact, the birds continue their attacks unabated and they kill Mr Trigg. When Nat finds Mr Trigg's body, Du Maurier draws our attention to the gun lying by his side.

The silent radio represents man's helplessness in the face of nature. Early in the story, for example, the radio acts as a source of information and comfort to Nat and his family, by stating that they are not the only victims and by instructing them what to do. But once the programmes stop, it becomes clear that Nat's society is completely unable to cope with the birds' attacks. Nat and his family are, therefore, alone in their struggle to survive. The closing image of the story, in which Nat listens to the silent radio, is a poignant reminder of this.