State wildlife officials were going door-to-door in Arkansas, to collect dead birds after thousands mysteriously fell from the sky!

From DISPERSANTS, perhaps?
FROM REUTERS--READ THE STORY HERE:
http://www.reuters.com/article/idUSTRE7010UO20110102
More:
Story on NY Daily News
And even more:
http://www.livescience.com/strangenews/birds-fall-from-sky-arkansas-hitchcock-110102.html