Hi, welcome to BYC!!
I have bantams also.. my 3 week olds look about the same as yours, so the age is probably pretty accurate.
My bantams really like watermelon, and worms. But you have to be sure that if you are giving them treats other than their chickstarter, you have to provide them with grit. That's little stones that they eat to help grind their food, since they don't have teeth. I bought some grit for small birds at
WalMart for a few bucks, and I just offer it to them in a shallow dish.
I have also weaned my chicks off the light.. I make sure they are not in a direct draft, and at night, I cover the brooder with a thin sheet, and they have done just fine.. mine have actually feathered out a little faster this way too.
I have a bantam or two that were skiddish of me when we brought them home. I just made sure never to pick them up from above.. I kind of scoop them up in my hand. I also make sure that I get down on their level some, so I'm not this huge being that poses a threat. They will come around, it just takes a little bit of time.
You are going to love having bantams.. they are so comical.
Here's a pic of mine....
This is my gang munching on dry oatmeal... they are not much for the wet kind.