There are a number of examples of irony in Du Maurier's story, "The Birds." One of the most striking can be found in the fate of Mrs Trigg, the farmer's wife. She demonstrates scepticism towards Nat when he tells her about the birds' attack on his home. In fact, she teases Nat by asking him if they were "real" birds with "proper feathers." Later in the story, however, Mrs Trigg is killed in a similar attack. In a further ironic twist, Mrs Trigg is killed in her own bedroom, just as Nat Hocken and his family were attacked in their bedrooms.
Similarly, when Nat finds Mr Trigg's body, he notes that his gun is lying "beside him." This is ironic because earlier in the story, Mr Trigg had offered a gun to Nat and talked of the "fun" that he and his friends intended to have by shooting the birds.
In employing irony when portraying the deaths of Mr and Mrs Trigg, Du Maurier not only demonstrates the power of nature but also mocks the idea that we can control and conquer it with man-made objects, like guns.