Also, I tried feeding some yogurt to my current chicks and they wouldn't touch it; gave it the evil eye like that little bowl was going to eat them! They even ran to the other side of the cage! 
I snuck one over on them, though; I put a layer of their chick starter on top of the yogurt. They all went "FOOD!!", charged it and ate as fast as they could. Since it was in a little container and there were six of them, they were all trying to scarf it as fast as possible.
 The first one to eat through to the yogurt/starter mix gave a 
really funny reaction!  
  She eventually decided that the gooey stuff was even 
better tasting than the starter. After she started really going after it, the other chicks followed suit. 
They still just get it as a treat, though. They grow like maniacs (and eat like it, too!) but just think of them as being like teenage boys. They eat a lot, run around and make a lot of racket while being cute, but they eventually grow out of it and start eating a more reasonable amount. Until then you just try to give them a balanced diet and a reasonable amount of treats. My older pullets are just getting close to laying and are now much more curious about different things to eat, so treats and scraps aren't a problem anymore.
I also found grapes and bread to be really popular with my chicks and usually all I needed to do was to sit quietly and patiently at their cage door while holding and sometimes jiggling the treat a little. Sooner or later one just can't resist their curiosity any longer and comes over to peck at it. If you cut the grapes into quarters first, they get the grape juice in/on their beak when they peck it and from there on it it's a mob scene when you even walk by with grapes!
I've heard pieces of watermelon can sometimes work even faster. Maybe it's the combination of red and green? Chickens seem to instinctively want to peck anything that's red or green. I'm going to try to get some later tonight and try it out on them tomorrow after their breakfast.