A hobby gardener builds a fox out of scrap metal, a mop head, and rubber booties, hoping it will frighten birds away from his vegetables. It doesn't work. The birds figure out the fake quickly, perch on it, and carry on eating his crops, growing fat and bold. The mood is wry and gently comic, and the speaker watches the man's efforts with a dry, amused distance rather than scorn.
The turn comes when a real fox appears and kills a slow blackbird. The birds, now wary, show they understood the difference between a pretend threat and a real one all along. The farmer's response is almost deflating: he harvests what's left, gives up gardening, feeds the birds, and buys a shotgun. The poem seems to suggest that nature is not easily fooled by cleverness, and that the man ends up outmatched and a little defeated. The final note is quietly ironic, since he gives up the garden but arms himself anyway.