You've probably read other threads where chickens devour snakes, mice, toads, other birds, etc. To them it's just like worms and bugs, only bigger. People choose to try to make chickens herbivores, but they're really omnivores and eat meat whenever and wherever they find it.
Mine love frostbitten venison (can't use it all up... I have deerhunting menfolk) that's thawed and tossed into their yard in small chunks. They love leftover liver, lunchmeat, fat cut off bacon, drippings from cooked bacon.... any meat that's a bit too old to feed the other 2-legged critters that live here.
Once my son left a suet cake from our wild birdfeeder on the ground, then came back for it, but it'd vanished. I'd watched 12 chickens have a happy afternoon around this marvelous, peanut buttery treat!