Hey, I know this thread is from way back, but i can tell you my chickens attack, eat and seemingly digest everything they can find. Alongside the pellets and grains I give them, they have free run on 3/4 of an acre including a less than savory compost heap and occasionally they break in to the house to eat the dog food.....
Nothing has killed them yet! They love table scraps of all descriptions (although I draw the line at giving them left-over curry or chicken....that CAN'T be right!) and will fight off my 4 cats and 1 dog in the daily challenge of the porridge pot and kids lunch-box remains....
Sweetcorn, worms, beetles, a number of small frogs, spinach (a favorite food), lots of grass, all manner of insects, dried up bits of cat/dog food, human food scraps, cucumbers and melons (mad for them....), cooked veg, cereal, mouldy bread no problem, cheese.....you name it, they eat it. Will let you know if they turn up anything poisonous to them....