In Alfred Hitchcock's "The Birds"?

In the movie The Birds, Alfred Hitchcock didn't want to give any explanation to why the birds acted the way they did. He didn't want the movie ending up a sci-fi movie than a thriller. Although in the restaurant scene where one person mentioned why the birds are doing what they are doing, give us some sense of why, it doesn't really answer why. There's no reason for it, it was just a vision of his when they wrote and made the film. Using the bird (based loosely on The Birds by Daphne du Maurier's short story) as a catalyst for the plight of the characters.

In my opinion, Alfred Hitchcock wanted to keep that a mystery but i think it had something to do with the environment. The birds did seem to attack for no apparent reason and thats the way he wanted to keep it. He was always good at leaving it up to your imagination. Great movie and special effects too. :)

That has to be the one movie that freaked me out when I was a teenager. I don't think it was ever explained why the birds attacked.

I agree with Devil (above). She took a pair of lovebirds in a cage to her friends house.

Perhaps the seagulls etc didnt like that and it it sparked off a hormone sensing thing in them (not wanting to see their winged friends in a cage) and so they started attacking humans.

I dont recall its ever clearly stated - I will have to get it and check it out.

It was never explained. The idea being we the viewers know as much as the characters.

I think it's something to do with the lovebirds she brought.