4 weeks old, we have only our list from MMcMurry Hatchery to go by, and all your BYC expert advice and pictures to guess what our 26 chicks are. These birds are so sweet and mellow. They are tiny compared to the others in our clutch. We are complete newbies, but, we are pretty sure that they are Sumatras. I should have taken the pictures with red backround to add to their vamp look.