I gave mine mealworms for chicks (they are just smaller) at just a few days old and they loved them and it did not hurt them at all. I also provided chick grit and they ate a little of it. Again, chick grit is just smaller than normal.. If they do not need it they will not eat it.
Edited to say that you do not want to give them a lot of them chick mealworms. Just a little for a treat. Keep the chick starter feed available at all times.
Edited to say that you do not want to give them a lot of them chick mealworms. Just a little for a treat. Keep the chick starter feed available at all times.