My Chicks will only eat Chick Starter

[Coykoi]

Mine are the same way, only crumble and if I give them wet crumble they gobble it up. I've mixed in finely chopped apple, romaine lettuce, boiled egg yolk, and water melon only to have them scratch it away from the crumble. They did go bananas for yogurt mixed with their crumble, then wetted down some more. On their trips outside they've played with blades of grass but not eaten it. They'll try it when they're ready, I just make it available every day or so. I also keep in mind that birds naturally behave as though everything new will eat them, even their food. It is funny when one tries something new and then they all rush in to try it!