Maranhão, Brazil - 3 November 2005: Rabid Vampire Bats Kill 23

Residents of marshy areas in the rain forest have suffered a spate of attacks by blood-sucking vampire bats. From the story on almendhar.com:

Mass attacks on humans have occurred in other cattle regions in Latin America when the cattle are suddenly removed, denying the bats their normal food.

The bats typically feed on mammalian blood.

Stories in Times (UK), the New Scientist, and the BBC. AAF thanks correspondent D Mahoney for this tip.