I have 15 six and a half week old chicks. I’m feeding Purina non medicated start and grow. I want to give them something more in this cold weather and just something more to enjoy period. I would like to give them something to scratch for but all the scratch I’ve seen says only feed to adult chickens. Could I give them cracked corn to scratch at or no?? I gave them some old hamburger buns the other evening and they showed zero interest.