According to popular belief, a bird hitting a window can be both a bad and a good sign.
It all depends on what kind of bird it was.
If the bird breaks when it hits the glass, this is a very bad sign, promising serious health problems.
If a bird hits a window and flies away, this is a good sign, foreshadowing positive changes in life.
If a pigeon, sparrow or swift hits a window, it means money, a promotion at work, or the arrival of relatives.
A titmouse and a swallow foretell good news and pleasant meetings.
If a forest bird, for example a cuckoo, hits the window, this is a bad sign, foreshadowing life's troubles and illnesses.