Love cheerios, and any other stale cereal that I'm throwing out.
Strawberries!! Grapes, their starter mash with milk, cabage leaves they didn't eat but had fun pecking it and carrying it around. Starter feed from my hand, or sprinkled on the ground, left over bread soaked in milk, carrots shredded, scrambled eggs!
Those things were the favorites with anything soaked in milk being the bestest!
I've thrown other table scraps out and now they ALL come running when they see me coming with the bucket!
My chicks range from 3 weeks, to almost 7 weeks. They also LOVE getting their own grass, and bugs, and when its cool, they stay in the run pecking and scratching away.