It is also my recollection that little chicks in their first few days/weeks can digest the chick starter crumble without access to grit, but if you are giving treats, they may need grit in order to break it down. I doubt yogurt falls into this category, but when I gave my little chicks yogurt they just walked in it and tracked it all over the place. I mix a few tablespoons of plain yogurt with live cultures in a morning warm mash I give to my laying chickens, but didn't have much luck with it with little chicks.