Mine are under the impression that cardinal feathers are a great source of extra food. The other day my dog startled a grass snake that goofed up and, in trying to get away, stuck its head inside the run. He made it back out alive but with a massive headache and missing a bit between the eyes. My youngest son thinks it's a hoot to toss in bits and pieces of whatever we have handy to see the chicken rugby game. Starts off with everyone in a circle staring at the new item. Someone will eventually get brave enough to peck at it. When that happens, everyone else goes "AHA! They ate it, it must be good" and the chase is on.
Even for the short amount of time I've had these birds I have reached the conclusion that the logic that says they will eventually learn what is and isn't a food item is bogus. The darn things eat everything that winds up in their area and I mean EVERYTHING. Leaves, grass, ants, mice, frogs, toads, if they can get it positioned right, down it goes. June bugs are especially tasty.