For chicks I've never had them be excited over treats right off the bat. I had to put chick feed in my hand and just relax my hand in the enclosure until the were curious enough to try. Then I started mixing in a few mealworms, and gradually introduced other treats. The initial trick was just getting them to associate my hand with food! After that, when they come to my hand for food I say "chick chick CHICKEN!" to associate them with the call and the food, that way as adults, wherever they are, they'll come running to me for treats!