My chickens are a little finicky and "independent" spirits. They only like what they can find themselves. I've seen them dig earthworms up from the ground, but if I put bait store worms on a plate they will turn their nose up at it. That goes for weeds, and other fresh greens too. They won't touch skinned apples or grapes, but will eat the wild berries off my bushes. I even have to scatter the oyster shell and grit on the ground because they won't eat it out of the bowls. The ONLY thing they will eat without foraging is the feed, though they have a nasty habit of kicking and pecking most of it out onto the ground.