The classic Alfred Hitchcock story.
You are in a desolate farmhouse, and you know that outside an enemy silently awaits. In the South of England,
a veteran of the recent war enjoys the peaceful countryside with his girlfriend as they watch the birds. Those birds that seemed to be so peaceful begin to persistently tap at the windows, and are out for blood. This part of the country is theirs, and the birds want you out.
(Audio is enhanced for better listening enjoyment. Although there is some tape squeal about mid-way through.)