Maybe the other food is getting stale. Ours do that sometimes They do eventually eat it all. You might try giving them a little less food, or mix some fresh in with the old. They wont get sick and die if they eat just scratch, but it is better for them to have the commercial feed too that has vitamins and such, especially in winter. I have noticed that ours really like the Purina Flock Raiser when it's fresh out of the bag, but when it is a week or so old they like it less. I also alternate between Flock Raiser and Layer, except for when it's cold as it has been these past couple of months, then I like the Flock Raiser cause it has more protein. But I think they do like the variety of different kinds of feed. We mix ours with either scratch or cracked corn, and switch back and forth between those, too. I suppose you could try taking the scratch away and just giving them the feed, but I think they will eventually eat it without resorting to that.