How would I go about poisoning birds?

What would be the most effective (in terms of number of casualties and cost) way to poison a large amount of wild birds? All these birds are dying in the South and Europe and no one knows why, I'd like to troll science but I don't know anything about poison. Could I just soak bird seed in something (maybe bleach, ammonia, or something), or maybe spray a bunch of Raid on it and dump it somewhere? Also, where would the best place to dump it be?

>>5
It would be better for domestic pets to be killed instead of natural birds.  These pets get into all sort of mischief and are a blight on the landscape.  If their owners liked their own pets, they would keep them at home.