Evil chickens?

Did you know chickens can be vicious, evil creatures???
The other evening, my two ducks went into the coop for the night,
and wouldn't come out - to go back to theirs.

I didn't see any harm, and let the stay with the chickens.

When I went to let them out to free range the next day,
Bucky's back was bloody, they were eating him alive!!! =(
He's recovering well, but it was horrific.