Chicks will also eat bugs. If you can give them access to bugs they would love that. Gnats (tiny flies) larvae, earthworms... The will eat flower seeds. Not all flower seeds, but it is a start.
I am feeding my corn meal (that you use to make corn bread), chia seeds, quinoa seeds. You can also use amaranth (pigweed) and some other small seeds. When they get big enough they will get oats, wheat, and corn, along with buckwheat and sunflower seeds.